#include <stdio.h>#define N 9int q[N] = {0};int cnt = 0;void print_q() {    int i;    for (i=0; i<N; i++) printf("%d ", q[i]);    printf("\n");    return;}int can_put(int m, int n) {    int i,j;    //row is ok    //colume    for (i=0; i<m; i++) {        if (q[i] == n) return 0;    }    //left-up    for (i=m-1,j=n-1; i>=0 && j>=0; i--,j--) {        if (q[i] == j) return 0;    }    //right-up    for (i=m-1,j=n+1; i>=0 && j<N; i--,j++) {        if (q[i] == j) return 0;    }    return 1;}void put_q(int m, int n) {    if (m == 0 && n >= N) {        printf("CNT: %d\n", cnt);    } else if (m >= N) {        print_q();        cnt++;        put_q(m-1, q[m-1]+1);    } else if (n >= N) {        put_q(m-1, q[m-1]+1);    } else if (can_put(m, n)) {        q[m] = n;        put_q(m+1, 0);    }    else {        put_q(m, n+1);    }    return;}int main(int argc, char* argv[]) {    put_q(0, 0);    return 0;}