hdu2732 （Leapin' Lizards）

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <stack>
#include <cctype>
#include <queue>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <climits>
#define lson rt<<1,l,mid
#define rson rt<<1|1,mid+1,r
#define fi first
#define se second
#define ping(x,y) ((x-y)*(x-y))
#define mst(x,y) memset(x,y,sizeof(x))
#define mcp(x,y) memcpy(x,y,sizeof(y))
using namespace std;
#define gamma 0.5772156649015328606065120
#define MOD 1000000007
#define inf 0x3f3f3f3f
#define N 2000000
#define maxn 500005
typedef pair<int,int> PII;
typedef long long LL;

map<PII,int>M;  ///map来记录点
int n,m,ccnt,S,T,len,peo,ans;
int head[1000],hcnt,d[1000],pre[1000],gap[1000],cur[1000];
char pic[50][50];
struct Crd{int x,y,v;}co[1000];
struct Node{int to,nxt,f;Node(){}Node(int a,int b,int c):to(a),nxt(b),f(c){}}node[N];
bool judge(int x,int y){    ///曼哈顿距离判断
    int temp=abs(co[x].x-co[y].x);
    temp+=abs(co[x].y-co[y].y);
    return temp<=m;
}
inline void add(int x,int y,int f){
    node[hcnt]=Node(y,head[x],f);head[x]=hcnt++;
    node[hcnt]=Node(x,head[y],0);head[y]=hcnt++;
}
void ISAP(int S,int T,int n){
    ans=0;
    int aug=inf,i,flag;
    int u,e,dis;
    mst(gap,0);mst(d,0);
    for(i=0;i<=n;++i)cur[i]=head[i];
    u=pre[S]=S;
    while(d[S]<n){
        flag=0;
        for(i=cur[u];~i;i=node[i].nxt){
            e=node[i].to;
            if(node[i].f>0&&d[u]==d[e]+1){
                flag=1;
                break;
            }
        }
        if(flag){
            pre[e]=u;
            cur[u]=i;
            aug=min(aug,node[i].f);
            u=e;
            if(u==T){
                while(u!=S){
                    u=pre[u];
                    node[cur[u]].f-=aug;
                    node[cur[u]^1].f+=aug;
                }
                u=S;
                ans+=aug;
                aug=inf;
            }
        }
        else{
            if(--gap[d[u]]==0)break;
            dis=n;
            cur[u]=head[u];
            for(int i=head[u];~i;i=node[i].nxt){
                e=node[i].to;
                if(node[i].f>0&&d[e]+1<dis){
                    dis=d[e]+1;
                    cur[u]=i;
                }
            }
            d[u]=dis;
            ++gap[dis];
            if(u!=S)u=pre[u];
        }
    }
}
int main(){
    int i,j,group,Case=0;
    scanf("%d",&group);
    while(group--){
        M.clear();
        len=hcnt=0;ccnt=0;
        mst(head,-1);
        scanf("%d%d",&n,&m);
        gets(pic[1]);
        for(i=1;i<=n;++i){
            gets(pic[i]+1);
            if(!len)len=strlen(pic[i]+1);
            for(j=1;j<=len;++j){
                if(pic[i][j]>‘0‘){
                    co[++ccnt].x=i;   ///ccnt是点的个数
                    co[ccnt].y=j;
                    co[ccnt].v=pic[i][j]-‘0‘;
                    M[make_pair(i,j)]=ccnt;
                }
            }
        }
        S=0;T=ccnt*2+1;
        for(i=1;i<=ccnt;++i){
            add(i,i+ccnt,co[i].v); ///柱子拆点连边
            if(co[i].x<=m||(n-co[i].x+1)<=m||co[i].y<=m||(len-co[i].y+1)<=m)
                add(i+ccnt,T,inf); ///与外界相通的柱子
            for(j=1;j<i;++j){
                if(judge(i,j)){
                    add(i+ccnt,j,inf); ///相互可达的柱子
                    add(j+ccnt,i,inf);
                }
            }
        }
        peo=0;    ///一共多少人
        for(i=1;i<=n;++i){
            gets(pic[i]+1);
            for(j=1;j<=len;++j){
                if(pic[i][j]==‘L‘){
                    ++peo;
                    int tt=M[make_pair(i,j)];
                    add(S,tt,1);
                }
            }
        }
        ISAP(S,T,T+1);
        ans=peo-ans;  
        printf("Case #%d: ",++Case);
        if(!ans)printf("no lizard was left behind.\n");
        else if(ans==1)printf("1 lizard was left behind.\n");
        else printf("%d lizards were left behind.\n",ans);
    }
    return 0;
}