python实现归并排序算法

理论不多说:

代码如下:

#!/usr/bin/python import sys def merge(array, q, p, r): left_array = array[q:p+1] right_array = array[p+1:r+1] left_array_num = len(left_array) right_array_num = len(right_array) i, j , k= [0, 0, q] while i < left_array_num and j < right_array_num: if (left_array[i] < right_array[j]): array[k] = left_array[i] i+=1 else: array[k] = right_array[j] j+=1 k+=1 while i < left_array_num: array[k] = left_array[i]; k+=1 i+=1 while j < right_array_num: array[k] = right_array[j] k+=1 j+=1 def merge_sort(array, q, r): if q < r: p = (q + r) / 2 merge_sort(array, q, p) merge_sort(array, p + 1, r) merge(array, q, p, r) if __name__ == "__main__": array = [2, 45, 5, 7, 34, 456, 345, 89, 8, 1, 341, 4, 98, 67] merge_sort(array, 0, len(array) - 1) for a in array: sys.stdout.write("%d " % a)

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