题解 | 约瑟夫环

#include<iostream>
#include<vector>

using namespace std;

int main() {
    int length, a, b;
    cin >> length >> a >> b;
    vector<int>vcc(length);
    for (int i = 0; i < length; i++) {
        vcc[i] = i;
    }
    int index = a;
    while (vcc.size() > 1) {
        int b1 = 1;
        while (b1 < b) {
            b1++;
            index = (index + 1) % vcc.size();
        }
        vcc.erase(vcc.begin() + index);
        a == vcc.size() - 1 ? a -= 1 : a;
    }
    cout << vcc[0];
}