Task Schedule HDU - 3572 + Alice's Chance POJ - 1698

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hdu這個題卡時間 之前的EK和dinic闆子根本過不了 才換成了isap

但是對isap還有一些不了解的地方 留個坑吧..

poj上還有一道基本一樣的

hdu 3572

#include <bits/stdc++.h>
using namespace std;
#define N 0x3f3f3f3f
 
struct node
{
    int v;
    int w;
    int next;
};
 
queue <int> que;
node edge[200010];
int first[100010],dis[100010],gap[100010],cur[100010],pre[100010];
int n,m,num,ss,ee;
 
void addedge(int u,int v,int w)
{
    edge[num].v=v;
    edge[num].w=w;
    edge[num].next=first[u];
    first[u]=num++;
    return;
}
 
void bfs()
{
    int i,u,v;
    while(!que.empty()) que.pop();
    memset(dis,-1,sizeof(dis));
    memset(gap,0,sizeof(gap));
    que.push(ee);
    dis[ee]=0;
    gap[0]++;
    while(!que.empty())
    {
        u=que.front();
        que.pop();
        for(i=first[u];i!=-1;i=edge[i].next)
        {
            v=edge[i].v;
            if(dis[v]==-1)
            {
                que.push(v);
                dis[v]=dis[u]+1;
                gap[dis[v]]++;
            }
        }
    }
    return;
}
 
int isap()
{
    int j,u,v,w,flow,minn,ans;
    bfs();
    memcpy(cur,first,sizeof(first));
    memset(pre,-1,sizeof(pre));
    u=ss,flow=N,ans=0;
    while(dis[ss]<num)
    {
        int &i=cur[u];
        for(;i!=-1;i=edge[i].next)
        {
            v=edge[i].v,w=edge[i].w;
            if(dis[v]+1==dis[u]&&w>0)
            {
                pre[v]=i;
                u=v,flow=min(flow,w);
                if(u==ee)
                {
                    while(u!=ss)
                    {
                        edge[pre[u]].w-=flow;
                        edge[pre[u]^1].w+=flow;
                        u=edge[pre[u]^1].v;
                    }
                    ans+=flow,flow=N;
                }
                break;
            }
        }
        if(i==-1)
        {
            if(--gap[dis[u]]==0) break;
            cur[u]=first[u];
            minn=num-1;
            for(j=first[u];j!=-1;j=edge[j].next)
            {
                v=edge[j].v,w=edge[j].w;
                if(w>0)
                {
                    minn=min(minn,dis[v]);
                }
            }
            dis[u]=minn+1;
            gap[dis[u]]++;
            if(u!=ss) u=edge[pre[u]^1].v;
        }
    }
    return ans;
}
 
int main()
{
    int t,cas,i,j,p,s,e,sum,res;
    scanf("%d",&t);
    for(cas=1;cas<=t;cas++)
    {
        scanf("%d%d",&n,&m);
        memset(first,-1,sizeof(first));
        num=0,ss=n+500+1,ee=n+500+2,sum=0;
        for(i=1;i<=n;i++)
        {
            scanf("%d%d%d",&p,&s,&e);
            addedge(ss,i,p);
            addedge(i,ss,0);
            sum+=p;
            for(j=s;j<=e;j++)
            {
                addedge(i,n+j,1);
                addedge(n+j,i,0);
            }
        }
        for(i=n+1;i<=n+500;i++)
        {
            addedge(i,ee,m);
            addedge(ee,i,0);
        }
        num=n+500+2;
        res=isap();
        if(res>=sum) printf("Case %d: Yes\n\n",cas);
        else printf("Case %d: No\n\n",cas);
    }
    return 0;
}      

poj 1698

#include <stdio.h>
#include <queue>
#include <cstring>
#include <algorithm>
using namespace std;
#define N 1e9

struct node
{
    int v;
    int w;
    int next;
};

node edge[100010];
int first[1010],dis[1010],gap[1010],cur[1010],pre[1010];
int n,num,ss,ee,ans;

void addedge(int u,int v,int w)
{
    edge[num].v=v;
    edge[num].w=w;
    edge[num].next=first[u];
    first[u]=num++;
    return;
}

void isap();
void bfs();

int main()
{
    int film[10];
    int t,i,j,k,d,w,sum;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%d",&n);
        memset(first,-1,sizeof(first));
        num=0,ss=n+350+1,ee=n+350+2,sum=0;
        for(i=1;i<=n;i++)
        {
            for(j=1;j<=7;j++)
            {
                scanf("%d",&film[j]);
            }
            scanf("%d%d",&d,&w);
            sum+=d;
            addedge(ss,i,d);
            addedge(i,ss,0);
            for(j=0;j<w;j++)
            {
                for(k=n+j*7+1;k<=n+j*7+7;k++)
                {
                    if(film[k-n-j*7]==1)
                    {
                        addedge(i,k,1);
                        addedge(k,i,0);
                    }
                }
            }
        }
        for(i=n+1;i<=n+350;i++)
        {
            addedge(i,ee,1);
            addedge(ee,i,0);
        }
        num=n+350+2;
        isap();
        if(ans>=sum) printf("Yes\n");
        else printf("No\n");
    }
    return 0;
}

void isap()
{
    int j,u,v,flow,minn;
    bfs();
    memcpy(cur,first,sizeof(first));
    memset(pre,-1,sizeof(pre));
    ans=0,u=ss,flow=N;
    while(dis[ss]<num)
    {
        int &i=cur[u];
        for(;i!=-1;i=edge[i].next)
        {
            v=edge[i].v;
            if(dis[v]+1==dis[u]&&edge[i].w>0)
            {
                pre[v]=i;
                u=v,flow=min(flow,edge[i].w);
                if(u==ee)
                {
                    while(u!=ss)
                    {
                        j=pre[u];
                        edge[j].w-=flow;
                        edge[j^1].w+=flow;
                        u=edge[j^1].v;
                    }
                    ans+=flow,flow=N;
                }
                break;
            }
        }
        if(i==-1)
        {
            if(--gap[dis[u]]==0) break;
            cur[u]=first[u];
            minn=num-1;
            for(j=first[u];j!=-1;j=edge[j].next)
            {
                if(edge[j].w>0)
                {
                    minn=min(minn,dis[edge[j].v]);
                }
            }
            dis[u]=minn+1;
            gap[dis[u]]++;
            if(u!=ss)
            {
                u=edge[pre[u]^1].v;
            }
        }
    }
    return;
}

void bfs()
{
    queue <int> que;
    int i,u,v;
    memset(dis,-1,sizeof(dis));
    memset(gap,0,sizeof(gap));
    que.push(ee);
    dis[ee]=0;
    while(!que.empty())
    {
        u=que.front();
        que.pop();
        gap[dis[u]]++;
        for(i=first[u];i!=-1;i=edge[i].next)
        {
            v=edge[i].v;
            if(dis[v]==-1)
            {
                dis[v]=dis[u]+1;
                que.push(v);
            }
        }
    }
    return;
}