[codevs1088]神经网络

题目←

阅读理解题

不良心出题人样例没给最后一层小于0的情况，wa了四次

#include<iostream>#include<cstdio>#include<algorithm>#include<queue>using namespace std;const long long MAXN = 1000 + 50;long long U[MAXN],C[MAXN],n,m;long long head[MAXN],next[MAXN << 1],tot;struct edge{    long long f,t,v;}l[MAXN << 1];void init(long long n){    for(long long i = 1;i <= n;i ++)        head[i] = -1;}void build(long long f,long long t,long long v){    l[++ tot] = (edge){f,t,v};    next[tot] = head[f];    head[f] = tot;}long long a,b,c;long long ru[MAXN];bool S[MAXN];queue <long long> q;long long deep[MAXN],maxd;struct zt{    long long num,v;}A[MAXN];long long cnt;bool cmp(zt a,zt b){    return a.num < b.num;}bool flag;int main(){    scanf("%lld%lld",&n,&m);    init(n);    for(long long i = 1;i <= n;i ++)        scanf("%lld%lld",&C[i],&U[i]);    for(long long i = 1;i <= m;i ++)    {        scanf("%lld%lld%lld",&a,&b,&c);        build(a,b,c);        ru[b] ++;    }    for(long long i = 1;i <= n;i ++)    {        if(!ru[i])q.push(i),S[i] = true;    }    while(!q.empty())    {        long long u = q.front();        q.pop();        if(!S[u])C[u] -= U[u];        //printf("u=%lld,C=%lld\n",u,C[u]);        for(long long i = head[u];i != -1;i = next[i])        {            long long t = l[i].t;            if(C[u] > 0)C[t] += C[u] * l[i].v;            ru[t] --;            if(!ru[t])            {                q.push(t);                deep[t] = deep[u] + 1;                maxd = max(maxd,deep[t]);            }        }    }    for(long long i = 1;i <= n;i ++)    {        if(deep[i] == maxd && C[i] > 0)        {            A[++ cnt].num = i;            A[cnt].v = C[i];            flag = true;        }    }    if(!flag)    {        printf("NULL");        return 0;    }    sort(A + 1,A + cnt + 1,cmp);    for(long long i = 1;i <= cnt;i ++)    {        printf("%lld %lld\n",A[i].num,A[i].v);    }    return 0;}