单源最短路径(可有负边权)(spfa)新模板

和原板子区别不大,更符合我的代码习惯

#include<cstdio>
#include<algorithm>
#include<cstring>
#include<queue>
using namespace std;
const int maxn = 2e5+5;
int n, m, head[maxn], s, num = -1, dis[maxn];
bool exist[maxn];
struct mint
{
    int nxt, v, w;    
}e[maxn];
inline void add(int u, int v, int w)
{
    e[++num].nxt = head[u];
    e[num].v = v;
    e[num].w = w;
    head[u] = num;    
}
inline void spfa()
{
    memset(dis,0x3f,sizeof(dis));
    memset(head,-1,sizeof(head));
    dis[1] = 0;
    queue<int> q;
    q.push(1);
   while(!q.empty()) { int u = q.front(); q.pop();
     exist[u] = 0;
for(int i = head[u];~i;i = e[i].nxt) { int v = e[i].v; if(dis[v] > dis[u] + e[i].w) { dis[v] = dis[u] + e[i].w; if(!exist[v]) { q.push(v); exist[v] = true; } } }    } } int main() { scanf("%d%d%d", &n, &m, &s); int a, b, c; for(int i = 1;i <= m;++i) { scanf("%d%d%d", &a, &b, &c); add(a,b,c); } spfa(); for(int i = 1;i <= n;++i) { printf("%d ", dis[i]); } return 0; }

 

posted @ 2021-07-21 08:10  Mint-hexagram  阅读(36)  评论(0编辑  收藏  举报