# hdu 2813 One fihgt one (二分图最优匹配，KM算法)

Posted by 111qqz on Thursday, June 2, 2016

## TOC

hdu 2813 题目链接

``````/* ***********************************************
Author :111qqz
Created Time :2016年06月02日 星期四 19时17分19秒
File Name :code/hdu/2813.cpp
************************************************ */

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <cmath>
#include <cstdlib>
#include <ctime>
#define fst first
#define sec second
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define ms(a,x) memset(a,x,sizeof(a))
typedef long long LL;
#define pi pair < int ,int >
#define MP make_pair

using namespace std;
const double eps = 1E-8;
const int dx4[4]={1,0,0,-1};
const int dy4[4]={0,-1,1,0};
const int inf = 0x3f3f3f3f;
const int N=205;
int n,m,k;
map<string,int>mp,mp2;
int tot1,tot2;
int w[N][N];
int lx[N],ly[N];
bool visx[N],visy[N];
int slk[N];

bool find( int u)
{
visx[u] = true;
for ( int v = 1 ; v <= m ; v++)
{
if (visy[v]) continue;
int tmp = lx[u] + ly[v] - w[u][v];
if (tmp==0)
{
visy[v] = true;
{
return true;
}
}else if (tmp<slk[v]) slk[v] = tmp;
}
return false;
}
int KM()
{
ms(lx,0xc0);
ms(ly,0);

for ( int  i = 1 ; i <= n ; i++)
for ( int j = 1 ; j <= m ; j++)
lx[i] = max(lx[i],w[i][j]);

//  for ( int i = 1 ; i <= n ; i++) cout<<"lx[i]:"<<lx[i]<<endl;
for ( int i = 1; i <= n ; i++)
{
ms(slk,0x3f);

while (1)
{
ms(visx,false);
ms(visy,false);

if (find(i)) break;

int d = inf;

for ( int j = 1 ; j <= m ; j++)
if (!visy[j]&&slk[j]<d) d = slk[j];

for ( int j = 1 ; j <= n ; j++) if (visx[j]) lx[j]-=d;
for ( int j = 1 ; j <= m ; j++) if (visy[j]) ly[j]+=d; else slk[j]-=d;
}
}
int res  =  0;
for ( int i = 1 ; i <= m ; i++)

return -res;
}
int main()
{
#ifndef  ONLINE_JUDGE
freopen("code/in.txt","r",stdin);
#endif
//	ios::sync_with_stdio(false);
while (scanf("%d%d%d",&n,&m,&k)!=EOF)
{
mp.clear();
mp2.clear();
tot1 = tot2 = 0;
ms(w,0xc0);
string u,v;
char tmpu[25],tmpv[25];
int cost;
for ( int i = 1 ; i <= k ; i++)
{
//cin>>u>>v>>cost;
scanf("%s %s %d",tmpu,tmpv,&cost);
u = string(tmpu);
v = string(tmpv);
if (!mp[u]) mp[u] = ++tot1;
if (!mp2[v]) mp2[v] = ++tot2;
w[mp[u]][mp2[v]] = -cost;
}

int ans = KM();
//cout<<ans<<endl;
printf("%d\n",ans);
}

#ifndef ONLINE_JUDGE
fclose(stdin);
#endif
return 0;
}
``````

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