题解 | #删数#

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

int main() {

    int n;
    while (cin >> n) {
        vector<int> vec;
        for (int i = 0; i < n; i++) {
            vec.push_back(i);
        }
        int flag = 1;
        int idx;
        int index = 0;
        while (true) {
            if (flag == 0)
                break;
            flag = 0;
            for (int i = 0; i < n; i++) {
                if (vec[i] != -1 && index == 2) {
                    vec[i] = -1;
                    index = 0;
                    idx = i;
                } else if (vec[i] != -1) {
                    index++;
                }
            }
            for (int i = 0; i < n; i++) {
                if (vec[i] >= 0) {
                    flag = 1;
                    break;
                }
            }
        }
        cout << idx << endl;
    }
}
// 64 位输出请用 printf("%lld")