hdu4185 Oil Skimming（二分匹配）

標籤：hdu   二分匹配   

# include <stdio.h># include <algorithm># include <string.h>using namespace std;int n,cot;int map[660],vis[660],pp[660][660],u[660][660];int bfs(int x){for(int i=1;i<=cot;i++){if(!vis[i]&&pp[x][i]){vis[i]=1;if(!map[i]||bfs(map[i])){map[i]=x;return 1;}}}return 0;}void judge(int x,int y){if(x<n-1&&u[x+1][y])pp[u[x][y]][u[x+1][y]]=pp[u[x+1][y]][u[x][y]]=1;//相連的“#”標記    if(y<n-1&&u[x][y+1])pp[u[x][y]][u[x][y+1]]=pp[u[x][y+1]][u[x][y]]=1;}int main(){int t,cas,i,j;char a[660][660];while(~scanf("%d",&t)){cas=0;while(t--){scanf("%d",&n);for(i=0;i<n;i++)scanf("%s",a[i]);            memset(u,0,sizeof(u));cot=0;for(i=0;i<n;i++){for(j=0;j<n;j++){if(a[i][j]=='#')u[i][j]=++cot;//為“#”標記}}memset(pp,0,sizeof(pp));for(i=0;i<n;i++){for(j=0;j<n;j++){if(u[i][j]){judge(i,j);}}}int res=0;memset(map,0,sizeof(map));for(i=1;i<=cot;i++)//一共1到cot個油田{memset(vis,0,sizeof(vis));if(bfs(i))res++;}printf("Case %d: %d\n",++cas,res/2);}}return 0;}