合并排序（递归拆分数组）

本文介绍了合并排序（递归拆分数组）的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

这是一个递归地将数组拆分成子集的函数。 我的问题是我不明白该函数将如何递归两次 .. Isn' t应该首先用新参数（a，i，mid）递归 ..如果已经破坏，它将如何返回并获取新参数（a，mid + 1，j）在第一个地方递归？ 我尝试过：

this is a function that split the array into subsets recursively .. My problem is that I don't understand how the function will recurse twice..Isn't is supposed to recurse first with new arguments(a,i,mid).. how will it then return and take new arguments(a,mid+1,j) if it already broke to recurse at first place? What I have tried:

void mergesort(int a[],int i,int j) { int mid; if(i<j) { mid=(i+j)/2; mergesort(a,i,mid); //left recursion mergesort(a,mid+1,j); //right recursion//my problem// merge(a,i,mid,mid+1,j); //merging of two sorted sub-arrays } }

推荐答案

Quote：

我不明白该函数将如何递归两次。

I don't understand how the function will recurse twice.

您的代码不会同时重复两次，它按顺序重复2次。

Your code don't recurs twice at same time, it recurs 2 times in sequence.

mergesort routine execution do stuff call mergesort(a,i,mid); // first recurs resume // resume execution when first recurs is finished do stuff call mergesort(a,mid+1,j); // second recurs resume // resume execution when second recurs is finished do stuff

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