这段代码为什么输入8 5没有任何输出

问题：N个人围成一圈，从第一个人开始报数，数到M的人出圈；再由下一个人重新开始报数，数到M的人出圈；…输出依次出圈的人的编号。N，M由键盘输入。

#include <iostream>
using namespace std;
bool a[101]
int main()
{
    int m, n;
    cin >> n >> m;
    cout << endl;
    for (int i = 1; i <=n; i++)
        a[i] = false;
    int f = 0, t = 0, s = 0;
    do {
        ++t;
        if (t == n + 1)
            t = 1;
        if (a[t] == false)
            ++s;
        if (s == m)
            {
                s = 0;
                cout << t << " ";
                a[t] == true;
                ++f;
            }
    } while (f != 0);
    return 0;
}

// Q839540.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>
using namespace std;

bool a[101];
int main()
{
    int m, n;
    cin >> n >> m;
    cout << endl;
    for (int i = 1; i <= n; i++)
        a[i] = false;
    int f = n, t = 0, s = 0;
    do {
        ++t;
        if (t == n + 1)
            t = 1;
        if (a[t] == false)
            ++s;
        if (s == m)
        {
            s = 0;
            cout << t << " ";
            a[t] = true;
            --f;
        }
    } while (f != 1);
    return 0;
}

8 5

5 2 8 7 1 4 6