多路归并排序

来源：互联网发布：便携电脑推荐知乎编辑：程序博客网时间：2024/06/06 02:15

题目要求：对整型链表数组（vector<list<int>> src）进行多路归并排序，得到一个有序链表（list<int> dest）。

代码实现：

#include<stdafx.h>#include <list>#include <vector>#include <iostream>#include <algorithm>using namespace std;list <int> merge(vector < list<int> > &src){size_t list_num = src.size();size_t total_elem = 0;    //对每个链表排序for (size_t i = 0; i != list_num; i++) {src[i].sort();total_elem += src[i].size();}    //堆的实现比较复杂，这里用最简单的方式，当链表的个数很大的时候，需要采用堆。list <int> dest;while (total_elem--) {int min= 0x7fffffff;int which= -1;for (int i = 0; i != list_num; i++) {if (src[i].empty())continue;if (src[i].front() < min) {min = src[i].front();which = i;}}if (min!= 0x7fffffff && which != -1) {src[which].pop_front();dest.push_back(min);}}return dest;}int main(){int n;vector < list<int> > src;cout<<"输入链表个数"<<endl;cin >> n; //链表个数for (int i = 0; i != n; i++) {int m;//第I个链表长度cout<<"输出第"<<i<<"个链表元素的个数"<<endl;cin >> m;list <int> tmp;//这里可以输入无序组数for (int j = 0; j != m; j++) {cout<<"输出第"<<i<<"个链表第"<<j<<"个元素个数"<<endl;int x;cin >> x;tmp.push_back(x);}src.push_back(tmp);}//输出所有链表for (int i = 0; i != n; i++) {for (list <int>::iterator it = src[i].begin(); it != src[i].end(); it++)cout << *it << " ";cout << endl;}//list <int> dest =merge(src);for (list <int>::iterator it = dest.begin(); it != dest.end(); it++)cout << *it << " ";cout << endl;getchar();return 0;}

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