单源最短路

4 6 1
1 2 2
2 3 2
2 4 1
1 3 5
3 4 3
1 4 4

0 2 4 3

#pragma GCC optimize(1)
#pragma GCC optimize(2)
#pragma GCC optimize(3)
#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
#define rep(i,j,k) for(register int i=(j);i<=(k);++i)
using namespace std;
template<class T> inline void read(T &x)
{
    x=0;
    register char c=getchar();
    register bool f=0;
    while(!isdigit(c))f^=c==‘-‘,c=getchar();
    while(isdigit(c))x=x*10+c-‘0‘,c=getchar();
    if(f)x=-x;
}
const int N = 10001;
const int M = 500001;
int n, m, s;
struct node{
    int a,b,c;
}g[M];
int dis[N];
bool flag[N];
inline bool cmp(const node &x,const node &y)
{
    return x.a<y.a;
}
int f[N], e[N];
int main()
{
    read(n), read(m), read(s);
    rep(i, 1, m)
        read(g[i].a), read(g[i].b), read(g[i].c);
    sort(g+1,g+1+m,cmp);
    memset(dis,-1,sizeof(dis));
    f[g[1].a]=1;
    rep(i,2,m)
        if(g[i].a!=g[i-1].a)
        {
            e[g[i-1].a]=i-1;
            f[g[i].a]=i;
        }
    e[g[m].a]=m;
    dis[s]=0;
    register int num=0;
    while(num<n)
    {
        register int mn=-1,u=-1;
        rep(i,1,n)
            if(flag[i]==0&&dis[i]!=-1)
                if(dis[i]<mn||mn==-1)
                    mn=dis[i],u=i;
        if(u==-1)
            break;
        flag[u]=1;
        num++;
        rep(i,f[u],e[u])
            if(i==0) break;
            else
            {
                register int v=g[i].b,val=g[i].c;
                if(dis[v]==-1||dis[v]>dis[u]+val)
                    dis[v]=dis[u]+val;
            }
    }
    rep(i,1,n)
        printf("%d ",dis[i]);
    return 0;
}