all possible n-queens

#include<stdio.h>
int board[10][10];
int N;
void print()
{
    for(int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            printf(" %d ", board[i][j]);
        }
        printf("\n");
    }
    printf("\n");
}
int isSafe(int row, int col)
{
    int i, j;
    for(i = 0; i < col; i++)
        if (board[row][i])
            return 0;
    for(i=row, j=col; i>=0 && j>=0; i--, j--)
        if (board[i][j])
            return 0;
    for(i=row, j=col; j>=0 && i<N; i++, j--)
        if (board[i][j])
            return 0;
    return 1;
}
int solve(int col)
{
    if(col == N) {
        print();
        return 1;
    }
    int res = 0;
    for(int i = 0; i < N; i++) {
        if(isSafe(i, col)) {
            board[i][col] = 1;
            res = solve(col + 1) || res;
            board[i][col] = 0;
        }
    }
    return res;
}
int main()
{
	scanf("%d", &N);
    solve(0);
    return 0;
}