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""" |
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Project Euler Problem 13: Large Sum |
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=================================== |
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.. module:: solutions.problem13 |
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:synopsis: My solution to problem #13. |
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The source code for this problem can be |
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`found here <https://bitbucket.org/nekedome/project-euler/src/master/solutions/problem13.py>`_. |
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Problem Statement |
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################# |
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Work out the first ten digits of the sum of the following one-hundred 50-digit numbers. |
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.. math:: |
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37107287533902102798797998220837590246510135740250 \\\\ |
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46376937677490009712648124896970078050417018260538 \\\\ |
20
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74324986199524741059474233309513058123726617309629 \\\\ |
21
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91942213363574161572522430563301811072406154908250 \\\\ |
22
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23067588207539346171171980310421047513778063246676 \\\\ |
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89261670696623633820136378418383684178734361726757 \\\\ |
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28112879812849979408065481931592621691275889832738 \\\\ |
25
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44274228917432520321923589422876796487670272189318 \\\\ |
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47451445736001306439091167216856844588711603153276 \\\\ |
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70386486105843025439939619828917593665686757934951 \\\\ |
28
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62176457141856560629502157223196586755079324193331 \\\\ |
29
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64906352462741904929101432445813822663347944758178 \\\\ |
30
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92575867718337217661963751590579239728245598838407 \\\\ |
31
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58203565325359399008402633568948830189458628227828 \\\\ |
32
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80181199384826282014278194139940567587151170094390 \\\\ |
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35398664372827112653829987240784473053190104293586 \\\\ |
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86515506006295864861532075273371959191420517255829 \\\\ |
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71693888707715466499115593487603532921714970056938 \\\\ |
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54370070576826684624621495650076471787294438377604 \\\\ |
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53282654108756828443191190634694037855217779295145 \\\\ |
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36123272525000296071075082563815656710885258350721 \\\\ |
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45876576172410976447339110607218265236877223636045 \\\\ |
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17423706905851860660448207621209813287860733969412 \\\\ |
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81142660418086830619328460811191061556940512689692 \\\\ |
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51934325451728388641918047049293215058642563049483 \\\\ |
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62467221648435076201727918039944693004732956340691 \\\\ |
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15732444386908125794514089057706229429197107928209 \\\\ |
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55037687525678773091862540744969844508330393682126 \\\\ |
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18336384825330154686196124348767681297534375946515 \\\\ |
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80386287592878490201521685554828717201219257766954 \\\\ |
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78182833757993103614740356856449095527097864797581 \\\\ |
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16726320100436897842553539920931837441497806860984 \\\\ |
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48403098129077791799088218795327364475675590848030 \\\\ |
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87086987551392711854517078544161852424320693150332 \\\\ |
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59959406895756536782107074926966537676326235447210 \\\\ |
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69793950679652694742597709739166693763042633987085 \\\\ |
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41052684708299085211399427365734116182760315001271 \\\\ |
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65378607361501080857009149939512557028198746004375 \\\\ |
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35829035317434717326932123578154982629742552737307 \\\\ |
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94953759765105305946966067683156574377167401875275 \\\\ |
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88902802571733229619176668713819931811048770190271 \\\\ |
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25267680276078003013678680992525463401061632866526 \\\\ |
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36270218540497705585629946580636237993140746255962 \\\\ |
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24074486908231174977792365466257246923322810917141 \\\\ |
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91430288197103288597806669760892938638285025333403 \\\\ |
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34413065578016127815921815005561868836468420090470 \\\\ |
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23053081172816430487623791969842487255036638784583 \\\\ |
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11487696932154902810424020138335124462181441773470 \\\\ |
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63783299490636259666498587618221225225512486764533 \\\\ |
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67720186971698544312419572409913959008952310058822 \\\\ |
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95548255300263520781532296796249481641953868218774 \\\\ |
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76085327132285723110424803456124867697064507995236 \\\\ |
70
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37774242535411291684276865538926205024910326572967 \\\\ |
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23701913275725675285653248258265463092207058596522 \\\\ |
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29798860272258331913126375147341994889534765745501 \\\\ |
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18495701454879288984856827726077713721403798879715 \\\\ |
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38298203783031473527721580348144513491373226651381 \\\\ |
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34829543829199918180278916522431027392251122869539 \\\\ |
76
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40957953066405232632538044100059654939159879593635 \\\\ |
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29746152185502371307642255121183693803580388584903 \\\\ |
78
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41698116222072977186158236678424689157993532961922 \\\\ |
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62467957194401269043877107275048102390895523597457 \\\\ |
80
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23189706772547915061505504953922979530901129967519 \\\\ |
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86188088225875314529584099251203829009407770775672 \\\\ |
82
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11306739708304724483816533873502340845647058077308 \\\\ |
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82959174767140363198008187129011875491310547126581 \\\\ |
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97623331044818386269515456334926366572897563400500 \\\\ |
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42846280183517070527831839425882145521227251250327 \\\\ |
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55121603546981200581762165212827652751691296897789 \\\\ |
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32238195734329339946437501907836945765883352399886 \\\\ |
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75506164965184775180738168837861091527357929701337 \\\\ |
89
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62177842752192623401942399639168044983993173312731 \\\\ |
90
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32924185707147349566916674687634660915035914677504 \\\\ |
91
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99518671430235219628894890102423325116913619626622 \\\\ |
92
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73267460800591547471830798392868535206946944540724 \\\\ |
93
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76841822524674417161514036427982273348055556214818 \\\\ |
94
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97142617910342598647204516893989422179826088076852 \\\\ |
95
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87783646182799346313767754307809363333018982642090 \\\\ |
96
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10848802521674670883215120185883543223812876952786 \\\\ |
97
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71329612474782464538636993009049310363619763878039 \\\\ |
98
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62184073572399794223406235393808339651327408011116 \\\\ |
99
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66627891981488087797941876876144230030984490851411 \\\\ |
100
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60661826293682836764744779239180335110989069790714 \\\\ |
101
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85786944089552990653640447425576083659976645795096 \\\\ |
102
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66024396409905389607120198219976047599490197230297 \\\\ |
103
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64913982680032973156037120041377903785566085089252 \\\\ |
104
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16730939319872750275468906903707539413042652315011 \\\\ |
105
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94809377245048795150954100921645863754710598436791 \\\\ |
106
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78639167021187492431995700641917969777599028300699 \\\\ |
107
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15368713711936614952811305876380278410754449733078 \\\\ |
108
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40789923115535562561142322423255033685442488917353 \\\\ |
109
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44889911501440648020369068063960672322193204149535 \\\\ |
110
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41503128880339536053299340368006977710650566631954 \\\\ |
111
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81234880673210146739058568557934581403627822703280 \\\\ |
112
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82616570773948327592232845941706525094512325230608 \\\\ |
113
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22918802058777319719839450180888072429661980811197 \\\\ |
114
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77158542502016545090413245809786882778948721859617 \\\\ |
115
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72107838435069186155435662884062257473692284509516 \\\\ |
116
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20849603980134001723930671666823555245252804609722 \\\\ |
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53503534226472524250874054075591789781264330331690 |
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Solution Discussion |
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################### |
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122
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Simply use Python's arbitrary precision arithmetic to compute this large sum, then divide by the appropriate power of |
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:math:`10` to leave the :math:`10` most significant digits. |
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Solution Implementation |
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####################### |
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.. literalinclude:: ../../solutions/problem13.py |
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:language: python |
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:lines: 133- |
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""" |
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from lib.digital import num_digits |
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def solve(): |
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""" Compute the answer to Project Euler's problem #13 """ |
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139
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# Build a list of integers |
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numbers = """ |
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37107287533902102798797998220837590246510135740250 |
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46376937677490009712648124896970078050417018260538 |
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74324986199524741059474233309513058123726617309629 |
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91942213363574161572522430563301811072406154908250 |
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23067588207539346171171980310421047513778063246676 |
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89261670696623633820136378418383684178734361726757 |
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28112879812849979408065481931592621691275889832738 |
148
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44274228917432520321923589422876796487670272189318 |
149
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47451445736001306439091167216856844588711603153276 |
150
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70386486105843025439939619828917593665686757934951 |
151
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62176457141856560629502157223196586755079324193331 |
152
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64906352462741904929101432445813822663347944758178 |
153
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92575867718337217661963751590579239728245598838407 |
154
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58203565325359399008402633568948830189458628227828 |
155
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80181199384826282014278194139940567587151170094390 |
156
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35398664372827112653829987240784473053190104293586 |
157
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86515506006295864861532075273371959191420517255829 |
158
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71693888707715466499115593487603532921714970056938 |
159
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54370070576826684624621495650076471787294438377604 |
160
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53282654108756828443191190634694037855217779295145 |
161
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36123272525000296071075082563815656710885258350721 |
162
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45876576172410976447339110607218265236877223636045 |
163
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17423706905851860660448207621209813287860733969412 |
164
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81142660418086830619328460811191061556940512689692 |
165
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51934325451728388641918047049293215058642563049483 |
166
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62467221648435076201727918039944693004732956340691 |
167
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15732444386908125794514089057706229429197107928209 |
168
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55037687525678773091862540744969844508330393682126 |
169
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18336384825330154686196124348767681297534375946515 |
170
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80386287592878490201521685554828717201219257766954 |
171
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78182833757993103614740356856449095527097864797581 |
172
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16726320100436897842553539920931837441497806860984 |
173
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48403098129077791799088218795327364475675590848030 |
174
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87086987551392711854517078544161852424320693150332 |
175
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59959406895756536782107074926966537676326235447210 |
176
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69793950679652694742597709739166693763042633987085 |
177
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41052684708299085211399427365734116182760315001271 |
178
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65378607361501080857009149939512557028198746004375 |
179
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35829035317434717326932123578154982629742552737307 |
180
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94953759765105305946966067683156574377167401875275 |
181
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88902802571733229619176668713819931811048770190271 |
182
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25267680276078003013678680992525463401061632866526 |
183
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36270218540497705585629946580636237993140746255962 |
184
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24074486908231174977792365466257246923322810917141 |
185
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91430288197103288597806669760892938638285025333403 |
186
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34413065578016127815921815005561868836468420090470 |
187
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23053081172816430487623791969842487255036638784583 |
188
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11487696932154902810424020138335124462181441773470 |
189
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63783299490636259666498587618221225225512486764533 |
190
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67720186971698544312419572409913959008952310058822 |
191
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95548255300263520781532296796249481641953868218774 |
192
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76085327132285723110424803456124867697064507995236 |
193
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37774242535411291684276865538926205024910326572967 |
194
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23701913275725675285653248258265463092207058596522 |
195
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29798860272258331913126375147341994889534765745501 |
196
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18495701454879288984856827726077713721403798879715 |
197
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38298203783031473527721580348144513491373226651381 |
198
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34829543829199918180278916522431027392251122869539 |
199
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40957953066405232632538044100059654939159879593635 |
200
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29746152185502371307642255121183693803580388584903 |
201
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41698116222072977186158236678424689157993532961922 |
202
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62467957194401269043877107275048102390895523597457 |
203
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23189706772547915061505504953922979530901129967519 |
204
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86188088225875314529584099251203829009407770775672 |
205
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11306739708304724483816533873502340845647058077308 |
206
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82959174767140363198008187129011875491310547126581 |
207
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97623331044818386269515456334926366572897563400500 |
208
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42846280183517070527831839425882145521227251250327 |
209
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55121603546981200581762165212827652751691296897789 |
210
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32238195734329339946437501907836945765883352399886 |
211
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75506164965184775180738168837861091527357929701337 |
212
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62177842752192623401942399639168044983993173312731 |
213
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32924185707147349566916674687634660915035914677504 |
214
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99518671430235219628894890102423325116913619626622 |
215
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73267460800591547471830798392868535206946944540724 |
216
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76841822524674417161514036427982273348055556214818 |
217
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97142617910342598647204516893989422179826088076852 |
218
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87783646182799346313767754307809363333018982642090 |
219
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10848802521674670883215120185883543223812876952786 |
220
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71329612474782464538636993009049310363619763878039 |
221
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62184073572399794223406235393808339651327408011116 |
222
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66627891981488087797941876876144230030984490851411 |
223
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60661826293682836764744779239180335110989069790714 |
224
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85786944089552990653640447425576083659976645795096 |
225
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66024396409905389607120198219976047599490197230297 |
226
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64913982680032973156037120041377903785566085089252 |
227
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16730939319872750275468906903707539413042652315011 |
228
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94809377245048795150954100921645863754710598436791 |
229
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78639167021187492431995700641917969777599028300699 |
230
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15368713711936614952811305876380278410754449733078 |
231
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40789923115535562561142322423255033685442488917353 |
232
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44889911501440648020369068063960672322193204149535 |
233
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41503128880339536053299340368006977710650566631954 |
234
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81234880673210146739058568557934581403627822703280 |
235
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82616570773948327592232845941706525094512325230608 |
236
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22918802058777319719839450180888072429661980811197 |
237
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|
|
77158542502016545090413245809786882778948721859617 |
238
|
|
|
72107838435069186155435662884062257473692284509516 |
239
|
|
|
20849603980134001723930671666823555245252804609722 |
240
|
|
|
53503534226472524250874054075591789781264330331690 |
241
|
|
|
""" |
242
|
|
|
numbers = numbers.split("\n") |
243
|
|
|
numbers = [number.strip() for number in numbers] |
244
|
|
|
numbers = [int(number) for number in numbers if number != ""] |
245
|
|
|
|
246
|
|
|
# Sum the list of integers |
247
|
|
|
total = sum(numbers) |
248
|
|
|
|
249
|
|
|
# Compute the number of digits in the sum, and how many to truncate to give the top 10 digits |
250
|
|
|
target = 10 |
251
|
|
|
n_digits = num_digits(total) |
252
|
|
|
truncate_digits = n_digits - target |
253
|
|
|
|
254
|
|
|
# Compute the final answer (first 10 digits) |
255
|
|
|
answer = total // (10 ** truncate_digits) |
256
|
|
|
return answer |
257
|
|
|
|
258
|
|
|
|
259
|
|
|
expected_answer = 5537376230 |
|
|
|
|
260
|
|
|
|
This check looks for lines that are too long. You can specify the maximum line length.