递归8皇后，10皇后以上栈就爆了

#include <stdio.h>

#define N 9
int 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;
}