#coding=utf-8 # 計(jì)算和最大的子數(shù)組 def divide_a(low, high): return (low + high) / 2 def combine_a(left_sub, right_sub, cross_sub): if left_sub[2] > right_sub[2] and left_sub[2] > cross_sub[2]: return left_sub elif right_sub[2] > left_sub[2] and right_sub[2] > cross_sub[2]: return right_sub else: return cross_sub def find_max_cross(A, low, high, mid): left_sum = 0 left_max_sum =A[mid] left_max_low = mid for i in range(mid, low-1, -1): left_sum = A[i] + left_sum if left_max_sum < left_sum : left_max_low = i left_max_sum = left_sum right_sum = 0 right_max_sum = A[mid + 1] right_max_high = mid + 1 for i in range(mid + 1, high+1): right_sum = A[i] + right_sum if right_max_sum < right_sum: right_max_high = i; right_max_sum = right_sum; PRint (left_max_low, right_max_high, left_max_sum + right_max_sum) return (left_max_low, right_max_high, left_max_sum + right_max_sum) def divide_and_conquer_a(A, low, high): #攻克 if low == high: return (low, high, A[low]) #分解 mid = divide_a(low, high) #遞歸 left_sub = divide_and_conquer_a(A, low, mid) right_sub = divide_and_conquer_a(A, mid+1, high) cross_sub = find_max_cross(A, low, high, mid) #合并 return combine_a(left_sub, right_sub, cross_sub) if __name__ == "__main__": A = [13, -3, -25, 20, -3, -16, -23, 18, 20, -7, 12, -5, -22, 15, -4, 7] t = divide_and_conquer_a(A,0,15) print t
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