Maximum Number That Sum of the Prices Is Less Than or Equal to K - Problem

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int getBitLength(long long num) {
    if (num == 0) return 0;
    int length = 0;
    while (num > 0) {
        length++;
        num >>= 1;
    }
    return length;
}

long long countAccumulatedPrice(long long limit, int x) {
    long long total = 0;
    for (long long i = 1; i <= limit; i++) {
        int price = 0;
        int pos = x;
        int bitLength = getBitLength(i);
        while (pos <= bitLength) {
            if (i & (1LL << (pos - 1))) {
                price++;
            }
            pos += x;
        }
        total += price;
    }
    return total;
}

long long solution(int k, int x) {
    long long left = 1, right = 1000000;
    long long result = 0;
    
    while (left <= right) {
        long long mid = (left + right) / 2;
        long long accumulated = countAccumulatedPrice(mid, x);
        
        if (accumulated <= k) {
            result = mid;
            left = mid + 1;
        } else {
            right = mid - 1;
        }
    }
    
    return result;
}

int main() {
    int k, x;
    scanf("%d", &k);
    scanf("%d", &x);
    printf("%lld\n", solution(k, x));
    return 0;
}