AcWing 849. Dijkstra求最短路 I
原题链接
简单
作者:
no_one
,
2022-08-06 12:11:28
,
所有人可见
,
阅读 130
复习一下
#include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
const int N = 510;
int n, m;
int d[N];
int g[N][N];
bool yin[N];
int dijstra()
{
memset(d, 0x3f, sizeof d);
d[1] = 0;
for(int i = 0; i < n; i ++)
{
int t = -1;
for(int j = 1; j <= n; j ++)
if(!yin[j] && (t == -1 || d[t] > d[j]))
t = j;
for(int j = 1; j <= n; j ++)
d[j] = min(d[j], d[t] + g[t][j]);
yin[t] = true;
}
if(d[n] == 0x3f3f3f3f) return -1;
return d[n];
}
int main()
{
cin >> n >> m;
memset(g, 0x3f, sizeof g);
while(m --)
{
int a, b, c;
cin >> a >> b >> c;
g[a][b] = min(g[a][b], c);
}
int t = dijstra();
cout << t << endl;
return 0;
}