hdu1045 二分匹配板子

#include<iostream>
#include<cstdio>
#include<vector>
#include<cstring>
using namespace std;

const int MAXN = 10;
int n,nl,nr;
char graph[MAXN][MAXN];
int grow[MAXN][MAXN];
int gcol[MAXN][MAXN];

vector<int> g[MAXN];
int from[MAXN],tot;
int to[MAXN];
bool use[MAXN];

bool match(int x){
	for(int i = 0;i < g[x].size();i++)
		if(!use[g[x][i]]){
			use[g[x][i]] = true;
			if(from[g[x][i]] == -1||match(from[g[x][i]])){
				from[g[x][i]] = x;
				to[x] = g[x][i];                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
				return true;
			}
		}
	return false;
}
int hungary(){
	tot = 0;
	memset(from,255,sizeof(from));
	for(int i = 0;i < n;i++){
		memset(use,0,sizeof(use));
		if(match(i))
			++tot;
	}
	return tot;
}

void build(){
	memset(grow, -1, sizeof(grow));
	memset(gcol, -1, sizeof(gcol));

	nl = 0;nr =  0;
	for(int i = 0;i < n;i++)//ºáÏò±àºÅ 
		for(int j = 0;j < n;j++){
			if(graph[i][j] == '.'&&grow[i][j] == -1){
				for(int k = j;graph[i][k] == '.'&&k < n;k++){
					grow[i][k] = nl; 
				}
				nl++;
			}
			
		}
	for(int j = 0;j < n;j++)//×ÝÏò±àºÅ 
		for(int i = 0;i < n;i++){
			if(graph[i][j] == '.'&&gcol[i][j] == -1){
				for(int k = i;graph[k][j] == '.'&&k < n;k++){
					gcol[k][j] = nr; 
				}
				nr++;
			}
			
		}
		
	for(int i = 0;i < n;i++)
		for(int j = 0;j < n;j++){
			if(graph[i][j] == '.'){
				g[grow[i][j]].push_back(gcol[i][j]);
	//			g[gcol[i][j]].push_back(grow[i][j]);
			}	
		}
	 
		n = nl;
	/*
		for(int i = 0;i < n;i++){	
			for(int j = 0;j < g[i].size();j++){
				printf("%d ",g[i][j]);
			}
			printf("\n");
		}
	*/
		return;
}
int main(){
	while(scanf("%d",&n) != EOF){
		if(n == 0)break;
		for(int i = 0;i < n;i++){
			scanf("%s",graph[i]);
		}
		for(int i = 0;i < MAXN;i++)
			g[i].clear();
		build();
		printf("%d\n",hungary());
	}
	
	return 0;
}

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转载自blog.csdn.net/qq_37136305/article/details/83032703