AcWing 849. Dijkstra求最短路 I
朴素Dijkstra
1.dis[1] = 0, dis[i] = \(+\infty\)
2.for(int i = 0; i < n; i++)
s:当前已确定最短距离的点
t \(\leftarrow\) 不在s中的距离最近的点
s \(\leftarrow\) t
用t更新其他点的距离
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
const int N = 510;
int n, m;
int g[N][N];
int dist[N];
bool st[N];
int dijkstra()
{
memset(dist, 0x3f, sizeof dist);
dist[1] = 0;
for(int i = 0; i < n; i++)
{
int t = -1;
for(int j = 1; j <= n; j++)
if(!st[j] && (t == -1 || dist[t] > dist[j]))
t = j;
st[t] = true;
for(int j = 1; j <= n; j++)
dist[j] = min(dist[j], dist[t] + g[t][j]);
}
if(dist[n] == 0x3f3f3f3f) return -1;
return dist[n];
}
int main()
{
scanf("%d%d", &n, &m);
memset(g, 0x3f, sizeof g);
while(m--)
{
int a, b, c;
scanf("%d%d%d", &a, &b, &c);
g[a][b] = min(g[a][b], c);
}
int t = dijkstra();
printf("%d", t);
return 0;
}
AcWing 850. Dijkstra求最短路 II
标签:dist,记录,int,原题,Dijkstra,include,AcWing
From: https://www.cnblogs.com/YuukiAsuna/p/17114337.html