Codeforce 1957-B : A BIT of a Construction

Problem Link : https://codeforces.com/problemset/problem/1957/B

I have tried this problem by writing this code:

#include <bits/stdc++.h>
using namespace std;
 
int main () {
    unsigned test; cin >> test; // Non-negative
    while (test--) {
        int size, k;
        cin >> size >> k;
        vector<int> v;
        for (int i = 0; i < size; i++) {
            if (k == 0) {
                v.push_back(0);
                continue;
            }
            if (pow(2, i) == k) {
                v.push_back(pow(2, i));
                k -= pow(2, i);
            } else if (pow(2, i) < k && i != size - 1) {
                v.push_back(pow(2, i));
                k -= pow(2, i);
            }
            else {
                v.push_back(k);
                k = 0;
            }
        }
        for (auto as : v) cout << as << ' '; cout << endl;
        return 0;
}

Basically, I tried to generate as many as 10, 100, 1000,.... Because 10|100|1000|... has maximum 1’s after operation I hope. I expect someone will help me by telling what is wrong in this approch.

>Solution :

Use left shift operators: 1 << i instead of pow(2, i).
In C++, those kinda functions that you used didn’t give an accurate value.
You also can use this for the maximum value:

1 << (int) log2(k)) - 1

Another is:

k - (1 << (int) log2(k)) - 1)

The rest of the elements are 0. Of course, you have to handle for n = 1.