HDU4160 Dolls（最大匹配）

题意：长方块嵌套，不能旋转，严格递增，建立二分图
求最大匹配

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cmath>
#include<set>
#include<map>
#include<string>
#include<cstring>
#include<stack>
#include<queue>
#include<vector>
#include<cstdlib>
#define lson (rt<<1),L,M
#define rson (rt<<1|1),M+1,R
#define M ((L+R)>>1)
#define cl(a,b) memset(a,b,sizeof(a));
#define LL long long
#define P pair<int,int>
#define X first
#define Y second
#define pb push_back
#define fread(zcc)  freopen(zcc,"r",stdin)
#define fwrite(zcc) freopen(zcc,"w",stdout)
using namespace std;
const int maxn=805;
const int inf=999999;


vector<int> G[maxn];
int matching[maxn];
bool vis[maxn];
int Nx;
bool dfs(int u){
    int N=G[u].size();
    for(int i=0;i<N;i++){
        int v=G[u][i];
        if(vis[v])continue;
        vis[v]=true;
        if(matching[v]==-1||dfs(matching[v])){
            matching[v]=u;
            return true;
        }
    }
    return false;
}
int hungar(){
    int ans=0;
    cl(matching,-1);
    for(int i=0;i<Nx;i++){
        cl(vis,false);
        if(dfs(i))ans++;
    }
    return ans;
}
struct node{
    int w,l,h;
}p[maxn];
int main(){
    int n;
    while(~scanf("%d",&n)&&n){

        for(int i=0;i<n;i++){
            scanf("%d%d%d",&p[i].w,&p[i].l,&p[i].h);
        }

        for(int i=0;i<n;i++){
            for(int j=0;j<n;j++)if(j!=i&&p[i].w<p[j].w&&p[i].l<p[j].l&&p[i].h<p[j].h){
                G[i].pb(j);
            }
        }

        Nx=n;
        int ans=hungar();
        printf("%d\n",n-ans);
        for(int i=0;i<=n;i++)G[i].clear();
    }
    return 0;
}