用的是递归

不清楚哪里有问题

#include <iostream>
#include <string>
using namespace std;

int N;

void reverse (string &s, int indax) {
    int is = 1;
    for (int i = 0; i < N; i++) {
        if (s[i] != '1') {
            is = 0;
            break;
        }
    }
    if (is == 1) {
        return;
    }
    for (int i = 0; i < indax; i++) {
        s[i] == '0' ? s[i] = '1' : s[i] = '0';
    }
    for (int i = indax + 1; i < N; i++) {
        s[i] == '0' ? s[i] = '1' : s[i] = '0';
    }
    cout << s.c_str() << endl;
    reverse (s, ++indax);
}

int main () {
    cin >> N;
    cout << N << endl;

    string coin;
    for (int i = 0; i < N; i++) {
        coin[i] = '0';
    }
    coin[N] = '\0';
    reverse (coin, 0);
    return 0;
}