题解

#include <iostream>
using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    unsigned int n;
    int q;
    cin >> n >> q;
    long long total = 0;
    while (q--) {
        int k;
        cin >> k;
        int bit_pos = k - 1;
        unsigned int mask = 1U << bit_pos;
        if ((n & mask) == 0) {
            unsigned int x = mask - (n & (mask - 1));
            total += x;
            n += x;
        }
    }
    cout << total << endl;
    return 0;
}