hdu3572Task Schedule 最大流，判断满流 优化的SAP算法

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

const int N=1010,M=510000, INF=0x3f3f3f3f;
struct node
{
    int to,next,w;
}edge[M];
int head[N],numh[N],h[N],cure[N],pre[N];
//numh:GAP优化的统计高度数量数组; h：距离标号数组; cure:当前弧
int ans,tot;
void SAP(int s, int e,int n)
{
    int flow,u,tmp,neck,i;
    ans=0;
    for(i=1;i<=n;i++)
        cure[i]=head[i];
    numh[0]=n;
    u=s;
    while(h[s]<n)
    {
        if(u==e)
        {
            flow =INF;
            for(i=s;i!=e;i=edge[cure[i]].to)
            {
                if(flow>edge[cure[i]].w)
                {
                    neck=i;
                    flow =edge[cure[i]].w;
                }
            }
            for(i=s;i!=e;i=edge[cure[i]].to)
            {
                tmp=cure[i];
                edge[tmp].w-=flow;
                edge[tmp^1].w+=flow;
            }
            ans+=flow;
            u=neck;
        }
        for(i=cure[u];i!=-1;i=edge[i].next)
            if(edge[i].w && h[u]==h[edge[i].to]+1) break;
        if(i!=-1) {cure[u]=i;pre[edge[i].to]=u;u=edge[i].to;}
        else
        {
            if(0==--numh[h[u]]) break; //GAP优化
            cure[u]=head[u];
            for(tmp=n,i=head[u];i!=-1;i=edge[i].next)
                if(edge[i].w) tmp=min(tmp, h[edge[i].to]);
            h[u]=tmp+1;
            ++numh[h[u]];
            if(u!=s) u=pre[u];
        }
    }
}
void init()
{
    tot=0;
    memset(head,-1,sizeof(head));
    memset(pre,-1,sizeof(pre));
    memset(h,0,sizeof(h));
    memset(numh,0,sizeof(numh));

}
void addedge(int i,int j,int w)
{
    edge[tot].to=j;edge[tot].w=w;edge[tot].next=head[i];head[i]=tot++;
    edge[tot].to=i;edge[tot].w=0;edge[tot].next=head[j];head[j]=tot++;
}
int main()
{
    //freopen("test.txt","r",stdin);
    int n,m,i,j,k,cas,t=1,a,b,c,MAX,sum,s;
    scanf("%d",&cas);
    while(cas--)
    {
        scanf("%d%d",&n,&m);
        init();
        MAX=0;sum=0;s=n+1;
        for(i=1;i<=n;i++)
        {
            scanf("%d%d%d",&a,&b,&c);
            sum+=a;
            MAX=max(MAX,c);
            addedge(s,i,a);
            for(j=b;j<=c;j++)
                addedge(i,j+s,1);
        }
        k=s+1+MAX;
        for(i=1;i<=MAX;i++)
            addedge(s+i,k,m);
        SAP(s,k,k);
        printf("Case %d: ",t++);
        if(ans==sum) printf("Yes\n\n");
        else printf("No\n\n");
    }
    return 0;
}