spfa 一个跑判定负环， 一个跑源点的最短路

#include<stdio.h>
#include<string.h>
#include<stdbool.h>

#define N 1010
#define M 100010
#define INF 0x3f3f3f3f

int n, m, s;
int dist[N];
int count[N];
int que[N], head, tail;
bool inQue[N];
int h[N], cnt;

struct edge{
    int to;
    int next;
    int s;
}E[M];

void add(int v, int w, int s){
    E[++cnt].next = h[v];
    E[cnt].to = w;
    E[cnt].s = s;
    h[v] = cnt;
}

void spfa1(){
    memset(dist, 0x3f, sizeof dist);
    dist[s] = 0;
    que[++tail] = s, inQue[s] = true;

    while(head != tail){
        int t = que[++head];
        head %= N;
        inQue[t] = false;

        for(int i = h[t]; i != -1; i = E[i].next){
            int j = E[i].to;
            if(dist[j] > dist[t] + E[i].s){
                dist[j] = dist[t] + E[i].s;
                if(!inQue[j]){
                    que[++tail] = j;
                    tail %= N;
                    inQue[j] = true;
                }
            }
        }
    }
}

bool spfa2(){
    head = 0, tail = 0;
    memset(dist, 0, sizeof dist);
    memset(inQue, false, sizeof inQue);
    for(int i = 1; i <= n; i++){
        que[++tail] = i;
        inQue[i] = true;
    }

    while(head != tail){
        int t = que[++head];
        head %= N;
        inQue[t] = false;

        for(int i = h[t]; i != -1; i = E[i].next){
            int j = E[i].to;
            if(dist[j] > dist[t] + E[i].s){
                dist[j] = dist[t] + E[i].s;
                count[j] = count[t] + 1;

                if(count[j] >= n)  return true;
                if(!inQue[j]){
                    que[++tail] = j;
                    tail %= N;
                    inQue[j] = true;
                }
            }
        }
    }
    return false;
}

int main(){

    scanf("%d %d %d", &n, &m, &s);
    memset(h, -1, sizeof h);

    for(int i = 1; i <= m; i++){
        int a, b, c;
        scanf("%d %d %d", &a, &b, &c);
        add(a, b, c);
    }

    if(spfa2())  printf("-1");
    else{
        spfa1();
        for(int i = 1; i <= n; i++)
            if(dist[i] > INF / 2) printf("NoPath\n");
            else  printf("%d\n", dist[i]);
    }

    return 0;
}