P5960 【模板】差分约束算法

#include <bits/stdc++.h>
#define inf 2333333333333
#define N 1000010
#define p(a) putchar(a)
#define For(i,a,b) for(long long i=a;i<=b;++i)
//by war
//2020.8.5
using namespace std;

long long n,m,flag,x,y,v;
long long d[N],num[N];
bool vis[N];

struct node{
    long long n;
    long long v;
    node *next;
}*e[N];

queue<long long>q;

void in(long long &x){
    long long y=1;char c=getchar();x=0;
    while(c<'0'||c>'9'){if(c=='-')y=-1;c=getchar();}
    while(c<='9'&&c>='0'){ x=(x<<1)+(x<<3)+c-'0';c=getchar();}
    x*=y;
}
void o(long long x){
    if(x<0){p('-');x=-x;}
    if(x>9)o(x/10);
    p(x%10+'0');
}

void push(long long x,long long y,long long v){
    node *p;
    p=new node();
    p->n=y;
    p->v=v;
    if(e[x]==0)
        e[x]=p;
    else{
        p->next=e[x]->next;
        e[x]->next=p;
    }
}

void spfa(long long x){
    if(vis[x]||flag){
        flag=1;
        return;
    }
    vis[x]=1;
    for(node *i=e[x];i;i=i->next){
        if(flag) return;
        if(d[i->n]>d[x]+i->v){
            d[i->n]=d[x]+i->v;
            spfa(i->n);
        }
    }
    vis[x]=0;
}

signed main(){
    in(n);in(m);
    For(i,1,m){
        in(x);in(y);in(v);
        push(y,x,v);
    }
    For(i,1,n)
        push(0,i,0);
    For(i,1,n) d[i]=inf;
    spfa(0);
    if(!flag){
        For(i,1,n) o(d[i]),p(' ');
    }
    else cout<<"NO";
    return 0;
}