chen0040 /
pyalgs
| @@ 85-163 (lines=79) @@ | ||
| 82 | def create(): |
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| 83 | return MinPQ() |
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| 84 | ||
| 85 | ||
| 86 | class MaxPQ(object): |
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| 87 | pq = None |
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| 88 | N = 0 |
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| 89 | ||
| 90 | def __init__(self, capacity=None): |
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| 91 | if capacity is None: |
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| 92 | capacity = 10 |
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| 93 | self.pq = [0] * capacity |
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| 94 | ||
| 95 | def enqueue(self, key): |
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| 96 | if self.N == len(self.pq): |
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| 97 | self.resize(len(self.pq) * 2) |
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| 98 | self.N += 1 |
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| 99 | self.pq[self.N] = key |
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| 100 | self.swim(self.N) |
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| 101 | ||
| 102 | def swim(self, k): |
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| 103 | while k > 1: |
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| 104 | parent = k // 2 |
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| 105 | if greater(self.pq[k], self.pq[parent]): |
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| 106 | exchange(self.pq, k, parent) |
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| 107 | k = parent |
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| 108 | else: |
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| 109 | break |
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| 110 | ||
| 111 | def del_max(self): |
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| 112 | if self.is_empty(): |
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| 113 | return None |
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| 114 | ||
| 115 | key = self.pq[1] |
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| 116 | exchange(self.pq, 1, self.N) |
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| 117 | self.N -= 1 |
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| 118 | if self.N == len(self.pq) // 4: |
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| 119 | self.resize(len(self.pq) // 2) |
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| 120 | ||
| 121 | self.sink(self.pq, 1, self.N) |
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| 122 | return key |
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| 123 | ||
| 124 | @staticmethod |
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| 125 | def sink(tmp, k, n): |
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| 126 | ||
| 127 | while k * 2 <= n: |
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| 128 | child = k * 2 |
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| 129 | if child < n and greater(tmp[child + 1], tmp[child]): |
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| 130 | child = child + 1 |
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| 131 | if greater(tmp[child], tmp[k]): |
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| 132 | exchange(tmp, child, k) |
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| 133 | k = child |
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| 134 | else: |
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| 135 | break |
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| 136 | ||
| 137 | def resize(self, new_size): |
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| 138 | tmp = [0] * new_size |
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| 139 | for k in range(min(new_size, len(self.pq))): |
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| 140 | tmp[k] = self.pq[k] |
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| 141 | self.pq = tmp |
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| 142 | ||
| 143 | def is_empty(self): |
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| 144 | return self.N == 0 |
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| 145 | ||
| 146 | def size(self): |
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| 147 | return self.N |
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| 148 | ||
| 149 | def iterate(self): |
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| 150 | tmp = [0] * (self.N + 1) |
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| 151 | for k in range(self.N + 1): |
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| 152 | tmp[k] = self.pq[k] |
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| 153 | ||
| 154 | n = self.N |
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| 155 | while n >= 1: |
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| 156 | key = tmp[1] |
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| 157 | exchange(tmp, 1, n) |
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| 158 | n -= 1 |
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| 159 | self.sink(tmp, 1, n) |
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| 160 | yield key |
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| 161 | ||
| 162 | @staticmethod |
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| 163 | def create(): |
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| 164 | return MaxPQ() |
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| 165 | ||
| 166 | ||
| @@ 4-82 (lines=79) @@ | ||
| 1 | from pyalgs.algorithms.commons.util import less, exchange, greater |
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| 2 | ||
| 3 | ||
| 4 | class MinPQ(object): |
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| 5 | pq = None |
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| 6 | N = 0 |
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| 7 | ||
| 8 | def __init__(self, capacity=None): |
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| 9 | if capacity is None: |
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| 10 | capacity = 10 |
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| 11 | self.pq = [0] * capacity |
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| 12 | ||
| 13 | def enqueue(self, key): |
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| 14 | self.N += 1 |
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| 15 | if self.N == len(self.pq): |
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| 16 | self.resize(len(self.pq) * 2) |
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| 17 | ||
| 18 | self.pq[self.N] = key |
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| 19 | self.swim(self.N) |
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| 20 | ||
| 21 | def swim(self, k): |
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| 22 | while k > 1: |
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| 23 | parent = k // 2 |
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| 24 | if less(self.pq[k], self.pq[parent]): |
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| 25 | exchange(self.pq, k, parent) |
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| 26 | k = parent |
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| 27 | else: |
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| 28 | break |
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| 29 | ||
| 30 | def del_min(self): |
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| 31 | if self.is_empty(): |
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| 32 | return None |
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| 33 | ||
| 34 | key = self.pq[1] |
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| 35 | exchange(self.pq, 1, self.N) |
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| 36 | self.N -= 1 |
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| 37 | if self.N == len(self.pq) // 4: |
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| 38 | self.resize(len(self.pq) // 2) |
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| 39 | ||
| 40 | self.sink(self.pq, 1, self.N) |
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| 41 | return key |
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| 42 | ||
| 43 | @staticmethod |
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| 44 | def sink(tmp, k, n): |
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| 45 | ||
| 46 | while k * 2 <= n: |
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| 47 | child = k * 2 |
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| 48 | if child < n and less(tmp[child + 1], tmp[child]): |
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| 49 | child = child + 1 |
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| 50 | if less(tmp[child], tmp[k]): |
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| 51 | exchange(tmp, child, k) |
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| 52 | k = child |
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| 53 | else: |
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| 54 | break |
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| 55 | ||
| 56 | def resize(self, new_size): |
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| 57 | tmp = [0] * new_size |
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| 58 | for k in range(min(new_size, len(self.pq))): |
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| 59 | tmp[k] = self.pq[k] |
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| 60 | self.pq = tmp |
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| 61 | ||
| 62 | def is_empty(self): |
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| 63 | return self.N == 0 |
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| 64 | ||
| 65 | def size(self): |
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| 66 | return self.N |
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| 67 | ||
| 68 | def iterate(self): |
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| 69 | tmp = [0] * (self.N + 1) |
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| 70 | for k in range(self.N + 1): |
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| 71 | tmp[k] = self.pq[k] |
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| 72 | ||
| 73 | n = self.N |
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| 74 | while n >= 1: |
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| 75 | key = tmp[1] |
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| 76 | exchange(tmp, 1, n) |
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| 77 | n -= 1 |
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| 78 | self.sink(tmp, 1, n) |
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| 79 | yield key |
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| 80 | ||
| 81 | @staticmethod |
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| 82 | def create(): |
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| 83 | return MinPQ() |
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| 84 | ||
| 85 | ||
