luogu3371 【模板】单源最短路径 dijkstra堆优化
#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
using namespace std;
int n, m, s, dis[10005], din, uu, vv, ww, hea[10005], cnt;
bool vis[10005];
struct Node{
int idx, val;
}dui[1100005];
struct Edge{
int too, nxt, val;
}edge[1000005];
bool cmp(Node x, Node y){
return x.val>y.val;
}
void add_edge(int fro, int too, int val){
edge[++cnt].nxt = hea[fro];
edge[cnt].too = too;
edge[cnt].val = val;
hea[fro] = cnt;
}
int main(){
cin>>n>>m>>s;
for(int i=1; i<=m; i++){
scanf("%d %d %d", &uu, &vv, &ww);
add_edge(uu, vv, ww);
}
memset(dis, 0x3f, sizeof(dis));
dis[s] = 0;
dui[++din] = (Node){s, 0};
while(din){
Node x=dui[1];
pop_heap(dui+1, dui+1+din, cmp);
din--;
if(vis[x.idx]) continue;
vis[x.idx] = true;
for(int i=hea[x.idx]; i; i=edge[i].nxt){
int t=edge[i].too;
if(!vis[t] && dis[t]>dis[x.idx]+edge[i].val){
dis[t] = dis[x.idx] + edge[i].val;
dui[++din] = (Node){t, dis[t]};
push_heap(dui+1, dui+1+din, cmp);
}
}
}
for(int i=1; i<=n; i++)
if(dis[i]==0x3f3f3f3f) printf("2147483647 ");
else printf("%d ", dis[i]);
printf("\n");
return 0;
}
拙いものと思えども、
その手に握る其れこそが、
いつか幻想を生んでいく。