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  • ZOJ 3229 Shoot the Bullet [上下界最大流]

    ZOJ 3229 Shoot the Bullet

    题意:此生无悔入东方


    上下界最大流
    spj挂掉了我也不知道对不对,把代码放这里吧以后正常了可能会评测一下

    #include <iostream>
    #include <cstdio>
    #include <cstring>
    #include <algorithm>
    using namespace std;
    typedef long long ll;
    const int N=2005, M=4e5+5, INF=1e9;
    inline ll read(){
        char c=getchar();ll x=0,f=1;
        while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}
        while(c>='0'&&c<='9'){x=x*10+c-'0';c=getchar();}
        return x*f;
    }
    
    int n, m, extra[N], s, t, tot, c, b, x, l, r;
    int a[370][1005];
    struct edge{int v, c, f, ne, lower;}e[M];
    int cnt=1, h[N];
    inline int ins(int u, int v, int c, int b=0) { //printf("ins %d %d  %d  %d
    ",u,v,c,b);
    	e[++cnt]=(edge){v, c, 0, h[u], b}; h[u]=cnt;
    	e[++cnt]=(edge){u, 0, 0, h[v], b}; h[v]=cnt;
    	return cnt-1;
    }
    int q[N], head, tail, vis[N], d[N], cur[N];
    bool bfs(int s, int t) {
    	memset(vis, 0, sizeof(vis));
    	head=tail=1;
    	q[tail++]=s; d[s]=0; vis[s]=1;
    	while(head!=tail) {
    		int u=q[head++];
    		for(int i=h[u];i;i=e[i].ne) 
    			if(!vis[e[i].v] && e[i].c>e[i].f) {
    				vis[e[i].v]=1; d[e[i].v]=d[u]+1;
    				q[tail++]=e[i].v;
    				if(e[i].v == t) return true;
    			}
    	}
    	return false;
    }
    int dfs(int u, int a, int t) { 
    	if(u==t || a==0) return a;
    	int flow=0, f;
    	for(int &i=cur[u];i;i=e[i].ne) 
    		if(d[e[i].v]==d[u]+1 && (f=dfs(e[i].v, min(a, e[i].c-e[i].f), t))>0) {
    			flow+=f;
    			e[i].f+=f;
    			e[i^1].f-=f;
    			a-=f;
    			if(a==0) break;
    		}
    	if(a) d[u]=-1;
    	return flow;
    }
    int dinic(int s, int t) {
    	int flow=0;
    	while(bfs(s, t)) {
    		for(int i=0; i<=tot; i++) cur[i]=h[i];
    		flow+=dfs(s, INF, t); 
    	}
    	return flow;
    }
    
    int main() {
    	freopen("in","r",stdin);
    	while(scanf("%d%d",&n,&m)!=EOF) {
    		s=0; t=n+m+1; 
    		cnt=1; memset(h,0,sizeof(h)); memset(extra, 0, sizeof(extra));
    		for(int i=1; i<=m; i++) b=read(), ins(n+i, t, INF, b), extra[n+i]-=b, extra[t]+=b;
    		for(int i=1; i<=n; i++) {
    			a[i][0]=read(); 
    			c=read(); ins(s, i, c, 0);
    			for(int j=1; j<=a[i][0]; j++) 
    				x=read()+1, l=read(), r=read(), a[i][j]=ins(i, n+x, r-l, l), extra[i]-=l, extra[n+x]+=l;
    		}
    
    		int ss=n+m+2, tt=n+m+3, sum=0; 
    		tot=n+m+3;
    		for(int i=s; i<=t; i++) {
    			if(extra[i] > 0) ins(ss, i, extra[i]), sum+=extra[i];
    			if(extra[i] < 0) ins(i, tt, -extra[i]);
    		}
    		ins(t, s, INF);
    		int flow=dinic(ss, tt); //printf("sum %d %d
    ",sum,flow); 
    
    		if(flow != sum) puts("-1");
    		else {
    			printf("look %d
    ",e[cnt-1].f);
    			//e[cnt-1]=e[cnt]=edge();
    			e[cnt].f=0;
    			printf("%d
    ", dinic(s, t));
    			for(int i=1; i<=n; i++) 
    				for(int j=1; j<=a[i][0]; j++) x=a[i][j], printf("%d
    ", e[x].f + e[x].lower);
    		}
    		puts("");
    	}
    	return 0;
    }
    
    
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  • 原文地址:https://www.cnblogs.com/candy99/p/6637017.html
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