HDU 1869 floyd 求两点间的最短距离

来源：互联网发布：单片机项目私活编辑：程序博客网时间：2024/05/22 11:43

求两点之间的最短距离

//memset(map, 0x1ffffff, sizeof(map));//错误的初始化方式

正确使用memset的方式是，初始指定的是8位的数值。比如说memset(map, 0x3f, sizeof(map)); 则map如果是int类型，则被初始化为4个3f 即 0x3f3f3f3f

#include <iostream>using namespace std;#define N 105int n, m;int map[N][N];void floyd(){for(int i = 0; i < n; i++)for(int j = 0; j < n; j++)for(int k = 0; k < n; k++){if(map[j][i] + map[i][k] < map[j][k])map[j][k] = map[j][i] + map[i][k];}}int main(){while(~scanf("%d %d", &n, &m)){//memset(map, 0x1ffffff, sizeof(map));//错误的初始化方式for(int i = 0; i < N; i++)for(int j = 0; j < N; j++)map[i][j] = 0x1fffffff;int x, y;for(int i = 0; i < m; i++){scanf("%d %d", &x, &y);map[x][y] = map[y][x] = 1;}for(int i = 0; i < n; i++)map[i][i]  = 0;floyd();int flag = 0;for(int i = 0; i < n && flag == 0; i++){for(int j = 0; j < n; j++){if(map[i][j] > 7){flag = 1;break;}}}if(flag == 1)cout << "No" << endl;else cout << "Yes" << endl;}return 0;}