hdu 4160 dolls 最少路径覆盖

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最少路径覆盖 == n - 最大匹配
#include<iostream>#include<vector>#include<algorithm>#include<cstdio>#include<cstring>#include<string>#include<iomanip>#include<cassert>using namespace std;const int maxn = 1011;const int add = 500;struct zz{    int x;    int y;    int z;}zx[maxn];vector<int>g[maxn];int link[maxn];int use[maxn];int n;bool dfs(int now){    int to;    for(int i=0;i<g[now].size();i++)    {        to = g[now][i];        if( !use[to] )        {            use[to] = true;            if(link[to] == -1 || dfs(link[to]) )            {                link[to] = now;                return true;            }        }    }    return false;}int matching(){    int ans = 0;    memset(link,-1,sizeof(link));    memset(use,false,sizeof(use));    for(int i=1;i<=n;i++)    {        memset(use,false,sizeof(use));        if(dfs(i))        {            ans++;        }    }    return ans;}bool can(int i,int j){    if(zx[i].x < zx[j].x && zx[i].y < zx[j].y && zx[i].z < zx[j].z )    {        return true;    }    return false;}int main(){    while(cin>>n)    {        if(n==0)        {            break;        }        for(int i=1;i<maxn;i++)        {            g[i].clear();        }        for(int i=1;i<=n;i++)        {            cin>>zx[i].x>>zx[i].y>>zx[i].z;        }        int from;        int to;        for(int i=1;i<=n;i++)        {            for(int j=1;j<=n;j++)            {                if(can(i,j))                {                    from = i;                    to = j + add;                    g[from].push_back(to);                    g[to].push_back(from);                }            }        }        cout<< n - matching()<<endl;    }    return 0;}