Codeforces 378C

来源：互联网发布：服务器数据迁移流程图编辑：程序博客网时间：2024/06/04 23:23

DFS连通块，思路就是搜到底，然后一个一个回溯（填上X）上来

#include <iostream>#include <stdio.h>#include <string.h>#include <stack>#include <queue>#include <map>#include <set>#include <vector>#include <math.h>#include <algorithm>using namespace std;#define LL long longconst double pi = acos(-1.0);#define Len 200005#define mod 19999997const int INF = 0x3f3f3f3f;#define exp 1e-6#define N 520bool vis[N][N];char ma[N][N];int n,m,k;void DFS(int x,int y){    if(x<0||y<0||x>=n||y>=m||vis[x][y]||ma[x][y]=='#')        return;    vis[x][y]=1;     //一直搜到底啊     DFS(x-1,y);    DFS(x+1,y);    DFS(x,y-1);    DFS(x,y+1);    if(!k)        return;    ma[x][y]='X';    --k;}int main(){    cin>>n>>m>>k;    for(int i=0;i<n;i++)        scanf("%s",ma[i]);    int flag=0;    memset(vis,0,sizeof(vis));    for(int i=0;i<n;i++)    {        for(int j=0;j<m;j++)        {            if(ma[i][j]=='.')            {                DFS(i,j);                flag=1;                break;            }        }        if(flag)            break;    }    for(int i=0;i<n;i++)        printf("%s\n",ma[i]);}

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