kuangbin_ShortPath F (POJ 3259)

判环模板题 有了上一题的经验过得很轻松

除了因为spfa还不是很熟打错了两个字母 然后debug了一小会

#include <iostream>
#include <string>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <queue>
#include <map>
#include <vector>
#include <set>
#include <algorithm>
#define INF 0x3F3F3F3F
using namespace std;

int size, head[], next[], point[], val[];

void init()
{
    size = ;
    memset(head, -, sizeof head);
}

void add(int from, int to, int value)
{
    point[size] = to;
    val[size] = value;
    next[size] = head[from];
    head[from] = size++;
}

bool spfa(int s, int n)
{
    int dis[], time[];
    bool vis[];
    memset(dis, 0x3f, sizeof dis);
    memset(time, , sizeof time);
    memset(vis, false, sizeof vis);

    queue<int> q;
    q.push(s);
    dis[s] = ;
    vis[s] = true;
    while(!q.empty()){
        int u = q.front();
        q.pop();
        vis[u] = false;
        for(int i = head[u]; ~i; i = next[i]){
            int j = point[i];
            if(dis[j] > dis[u] + val[i]){
                dis[j] = dis[u] + val[i];
                if(!vis[j]){
                    //printf("dis[%d] = %d\n", j, dis[j]);
                    q.push(j);
                    vis[j] = true;
                    if(++time[j] > n) return true;
                }
            }
        }
    }
    return false;
}

int main()
{
    int f, n, m, w;
    scanf("%d", &f);
    while(f--){
        init();
        scanf("%d%d%d", &n, &m, &w);
        while(m--){
            int a, b, value;
            scanf("%d%d%d", &a, &b, &value);
            add(a, b, value);
            add(b, a, value);
        }
        while(w--){
            int from, to, value;
            scanf("%d%d%d", &from, &to, &value);
            add(from, to ,  - value);
        }
        if(spfa(, n)) puts("YES");
        else puts("NO");
    }
    return ;
}