是否超过最大递归深度？

Question

开始学习python，这是我尝试过的最大和子数组。以“最大递归深度超出比较”结尾。我的算法对我来说还可以。如果我做错了什么，请帮帮我。在

import sys
import math
def maxtuple(lss,rss):
    if lss[2] > rss[2]:
        return lss
    else:
        return rss
def crosssubarray(A, start, mid, end):
    ls=rs=-sys.maxsize
    maxleft=0
    maxright=0
    sum = 0;
    for i in reversed(range(start, mid)):
        sum = sum + A[i]
        print(i)
        if sum > ls:
            ls = sum
            maxleft = i
    sum = 0
    for i in range(mid+1, end):
        sum = sum+ A[i]
        if sum > rs:
            rs = sum
            maxright = i
    return (maxleft, maxright, ls+rs)

def maxsubarray(A,start,end):
    if start == end:
        return (start,end,A[start])
    else:
        mid = (start+end)/2
        lss = maxsubarray(A, start, mid)
        rss = maxsubarray(A, mid+1, end)
        css = crosssubarray(A, start, mid, end)
        maxsub = maxtuple(lss,rss)
        maxall = maxtuple(maxsub, css)
        return maxall

A = [13,-3,-25,20,-3,-16,-23,18,20,-7,12,-5,-22,15,-4,7]
print(maxsubarray(A,0,15))

Answer 1

您的问题在于此函数：

def maxsubarray(A,start,end):
    if start == end:
        return (start,end,A[start])
    else:
        mid = (start+end)/2
        lss = maxsubarray(A, start, mid)
        rss = maxsubarray(A, mid+1, end)
        css = crosssubarray(A, start, mid, end)
        maxsub = maxtuple(lss,rss)
        maxall = maxtuple(maxsub, css)
        return maxall

准确地说，前5行。在Python2.x中“工作”（不知道预期结果）的原因是/用于楼层划分，而在Python3.x中/用于浮点除法。由于浮点舍入误差，start很可能永远不会等于end。在

---

如果整数楼层除法是您要的，您可以将/替换为//。在

这样，错误将消失并返回(8, 10, 32)

Answer 2

您可以增加允许的堆栈深度-这样，就可以进行更深入的递归调用，如下所示：

import sys
sys.setrecursionlimit(10000) # 10000 is an example, try with different values

。。。但我建议您首先尝试优化代码，例如，使用迭代而不是递归。在