UVA - 11520 Fill the Square

各位置が周囲と等しくないようにマトリクスを記入する

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int MAXN = 20;

int n;
char map[MAXN][MAXN];

char fill(int row,int col){
    for (int ch = 'A'; ch <= 'Z'; ch++)
        if (ch != map[row][col-1] && ch != map[row][col+1]
                && ch != map[row+1][col] && ch != map[row-1][col])
            return ch;
    
}

void solve(){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            if (map[i][j] == '.')
                map[i][j] = fill(i,j);
    for (int i = 1; i <= n; i++)
        printf("%s
",map[i]+1);
}

int main(){
    int t,cas=1;
    scanf("%d",&t);
    while (t--){
        scanf("%d",&n);
        memset(map,0,sizeof(map));
        for (int i = 1; i <= n; i++)
            scanf("%s",map[i]+1);
        printf("Case %d:
",cas++);
        solve();
    }
    return 0;
}