BZOJ 2464: 中山市选[2009]小明的游戏 简单搜索

传送门：http://www.lydsy.com/JudgeOnline/problem.php?id=2464

简单搜索：把每一块分好后搜索就可以了

code：

#include<bits/stdc++.h>using namespace std;typedef long long LL;const int maxn = 510;const int inf=510*510;typedef pair<int,int>p;int dir[4][2]={0,1,0,-1,1,0,-1,0};inline void read(int &x){    x = 0;    char p = getchar();    while(!(p <= '9' && p >= '0'))p = getchar();    while(p <= '9' && p >= '0')x *= 10, x += p - 48, p = getchar();}char maze[maxn][maxn];int dp[maxn][maxn];int n,m;int main(){    while(scanf("%d%d",&n,&m)!=EOF)    {        if(n == 0 && m == 0) break;        for(int i=1;i<=n;i++)            scanf("%s",maze[i]+1);        for(int i=1;i<=n;i++)            for(int j=1;j<=m;j++)                 dp[i][j]=inf;        int x1,y1,x2,y2;        read(x1),read(y1),read(x2),read(y2),x1++,y1++,x2++,y2++;        dp[x1][y1]=0;        queue<p>q1,q2;q1.push(p(x1,y1));        while(q1.size())        {            p now=q1.front();q1.pop();            for(int i=0;i<4;i++)            {                int x=now.first+dir[i][0],y=now.second+dir[i][1];                if(x > n || x < 1 || y > m || y < 1) continue;                if(dp[x][y] <= dp[now.first][now.second]) continue;                if(maze[x][y] == maze[now.first][now.second])                    dp[x][y]=dp[now.first][now.second],q1.push(p(x,y));                else                    dp[x][y]=dp[now.first][now.second]+1,q2.push(p(x,y));            }            if(q1.empty()) swap(q1,q2);        }        printf("%d\n",dp[x2][y2]);    }    return 0;}