hdu 3572 最大流判断满流

#include<stdio.h>
#include<string.h>
#include<queue>
using namespace std;
#define inf 0x3fffffff
#define N 4000
struct node {
int u,v,w,next;
}bian[N*N*4];
int head[N],yong,n,s,t;
void init() {
memset(head,-1,sizeof(head));
yong=0;
}
void addedge(int u,int v,int w) {
bian[yong].u=u;
bian[yong].v=v;
bian[yong].w=w;
bian[yong].next=head[u];
head[u]=yong++;
}
int d[N];
int bfs() {
  int i,cur,v;
  queue<int>q;
  memset(d,0,sizeof(d));
  q.push(s);
  d[s]=1;
  while(!q.empty()) {
    cur=q.front();
    q.pop();
    for(i=head[cur];i!=-1;i=bian[i].next) {
        v=bian[i].v;
        if(bian[i].w&&!d[v]) {
            d[v]=d[cur]+1;
            if(v==t)
                return 1;
            q.push(v);
        }
    }
  }
  return 0;
}
int Min(int a,int b) {
return a>b?b:a;
}
int dfs(int u,int limit) {
   int cost=0,v,i,flow;
   if(u==t)//注意
    return limit;
   for(i=head[u];i!=-1;i=bian[i].next) {
    v=bian[i].v;
    if(bian[i].w&&d[v]==d[u]+1) {
        flow=dfs(v,Min(limit-cost,bian[i].w));
        if(flow>0) {//
            bian[i].w-=flow;
            bian[i^1].w+=flow;
            cost+=flow;
            if(limit==cost)//如果已经搜到了满流就跳出
                break;
        }
        else
            d[v]=-1;//如果流量等于零，再遇到这个点就进行不下去了
    }
   }
   return cost;
}
int dinic() {
int sum=0;
while(bfs())//建层次图
    sum+=dfs(s,inf);//多次dfs搜索s-t增光路求可行流
    return sum;
}
int main() {
   int tt,m,i,j,k,ma,a,b,c,sum,f=0;
   scanf("%d",&tt);
   while(tt--) {
        init();
    scanf("%d%d",&n,&m);
    ma=-1;
    s=0;sum=0;
    for(i=1;i<=n;i++) {
        scanf("%d%d%d",&a,&b,&c);
        sum+=a;
        addedge(s,i,a);//源点与任务建边
        addedge(i,s,0);
        if(ma<c)ma=c;
        for(j=b;j<=c;j++) {
            addedge(i,n+j,1);//任务与时间点建边
            addedge(n+j,i,0);
        }
    }
    t=n+ma+1;
    for(i=1;i<=ma;i++) {
        addedge(n+i,t,m);//时间点与汇点建边
        addedge(t,n+i,0);
    }
    k=dinic();//跑一边最大流
    if(k==sum)
        printf("Case %d: Yes\n",++f);
    else
        printf("Case %d: No\n",++f);
        printf("\n");
   }
return 0;
}