1 - master - 3445030/test

#include <stdio.h>

#define SIZE 64

int h, w;
char matr[SIZE][SIZE];
int hasRow[SIZE], hasCol[SIZE], hasAdd[2*SIZE], hasSub[2*SIZE];

int Solve(int r) {
    if (r == h) {
        return 1;
    }
    for (int c = 0; c < w; c++) {
        if (matr[r][c] == '.')
            continue;
        if (hasRow[r] || hasCol[c] || hasAdd[r+c] || hasSub[r-c + SIZE])
            continue;

        hasRow[r]++;
        hasCol[c]++;
        hasAdd[r+c]++;
        hasSub[r-c + SIZE]++;
        char old = matr[r][c];
        matr[r][c] = 'X';

        if (Solve(r+1))
            return 1;
    
        matr[r][c] = old;
        hasRow[r]--;
        hasCol[c]--;
        hasAdd[r+c]--;
        hasSub[r-c + SIZE]--;
    }

    return 0;
}

int main() {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);

    scanf("%d%d", &h, &w);
    for (int i = 0; i < h; i++)
        scanf("%s", matr[i]);

    if (!Solve(0)) {
        printf("NO\n");
        return 0;
    }

    printf("YES\n");

     for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++)
            if (matr[i][j] == '?')
                matr[i][j] = '.';
        printf("%s\n", matr[i]);
    }

    return 0;
}