Dijkstra板子n^2(起点为0,而不是1)
#include <bits/stdc++.h>
#define INF 0x3f3f3f3f
using namespace std;
int n,m;//节点数和边数
int dis[105];//记录每个点到源点的距离
int mapi[105][105];//记录边
int vis[105];//记录这个点是否被选中过
void dijkstra(int s){//s是源点
memset(dis,INF,sizeof(dis));
memset(vis,0,sizeof(vis));
int start = s;
vis[start] = 1;
dis[0] = 0;
for(int i = 0;i < n;i++){
dis[i] = min(dis[i],mapi[start][i]);
}
for(int i = 0;i < n-1;i++){
int mini = INF;
for(int j = 0;j < n;j++){
if(vis[j]==0 && dis[j]<mini){
mini = dis[j];
start = j;
}
}
vis[start] = 1;
for(int k = 0;k < n;k++)
dis[k] = min(dis[k],dis[start]+mapi[start][k]);
}
}
int main()
{
while(cin>>n>>m){
memset(mapi,INF,sizeof(mapi));
for(int i = 0;i < m;i++){
int a,b,c;
cin>>a>>b>>c;
mapi[a][b] = c;
}
for(int i = 0;i < n;i++){
for(int j = 0;j < n;j++){
if(i == j)
mapi[i][j] = 0;
}
}
dijkstra(0);
for(int i = 0;i < n;i++)
cout<<" "<<dis[i];
cout<<endl;
}
return 0;
}
给出一组数据:
5 6
0 1 5
0 2 8
1 2 1
1 3 3
3 4 7
1 4 2
输出:0 5 6 8 7