过了 但还有点疑问

自己感觉前后两次只是改了判断方式 结果第一次没过第二次过了(汗)

#include <cstdio>

bool a[14][14] = {0};
int n, cnt = 0, ans[14], tot = 1;
bool judge(int step, int col) {
    for (int i = 1; i <= n; i++)
        if (a[i][col] && i != step)
            return 0;
    for (int i = 1; i <= n; i++) {
        int j = i - (step - col);
        if (a[i][j] && i != step && j != col)
            return 0;
    }
    for (int i = 1; i <= n; i++) {
        int j = (step + col) - i;
        if (a[i][j] && i != step && j != col)
            return 0;
    }
    return 1;
}
void dfs(int step, int col) {
    if (step == n + 1) {
        if (tot <= 3) {
            tot++;
            for (int i = 2; i <= n + 1; i++)
                printf("%d ", ans[i]);
            printf("\n");
        }
        cnt++;
        return;
    }
    for (int j = 1; j <= n; j++) {
        if (judge(step, j)) {
            a[step][j] = 1;
            step++;
            ans[step] = j;
            dfs(step, j);
            step--;
            a[step][j] = 0;
        }
    }
}
int main() {
    scanf("%d", &n);
    dfs(1, 1);
    printf("%d", cnt);
    return 0;
}

#include <cstdio>

bool a[14][14] = {0}, forwardSlash[13] = {0}, backSlash[27] = {0}, colA[14] = {0};
int n, cnt = 0, ans[14], tot = 1;
bool judge(int step, int col) {
    if (forwardSlash[step - col] || backSlash[step + col] || colA[col])
        return 0;
    return 1;
}
void dfs(int step, int col) {
    if (step == n + 1) {
        if (tot <= 3) {
            tot++;
            for (int i = 1; i <= n; i++)
                printf("%d ", ans[i]);
            printf("\n");
        }
        cnt++;
        return;
    }
    for (int j = 1; j <= n; j++) {
        if (judge(step, j)) {
            forwardSlash[step - j] = 1;
            backSlash[step + j] = 1;
            colA[j] = 1;
            ans[step] = j;
            step++;
            dfs(step, j);
            step--;
            forwardSlash[step - j] = 0;
            backSlash[step + j] = 0;
            colA[j] = 0;
        }
    }
}
int main() {
    scanf("%d", &n);
    dfs(1, 1);
    printf("%d", cnt);
    return 0;
}