// LeetCode 2749: Minimum Operations To Make The Integer Zero
// 難度: Medium
// 日期: 2025-09-05

using System;
using System.Collections.Generic;
using System.Linq;

public class Solution
{
    public int MakeTheIntegerZero(int num1, int num2)
    {
        for (int k = 1; k <= 60; k++)
        {
            long target = (long)num1 - (long)k * num2;

            if (target < 0) continue;

            int bitCount = CountSetBits(target);

            if (bitCount <= k && k <= target)
            {
                return k;
            }
        }

        return -1;
    }

    private int CountSetBits(long n)
    {
        int count = 0;
        while (n > 0)
        {
            // 方法一
            // count += (int)(n & 1);
            // n >>= 1;

            // 方法二
            count++;
            n &= n - 1;
        }
        return count;
    }
}

public class Program
{
    public static void Main()
    {
        Solution solution = new Solution();
        TestCase1(solution);
        TestCase2(solution);
    }

    static void TestCase1(Solution solution)
    {
        int num1 = 3, num2 = -2;
        int expected = 3;
        int actual = solution.MakeTheIntegerZero(num1, num2);

        Console.WriteLine("Test 1:");
        Console.WriteLine($"Input: num1 = {num1}, num2 = {num2}");
        Console.WriteLine($"Expected: {expected}");
        Console.WriteLine($"Actual: {actual}");
        Console.WriteLine($"Result: {(actual == expected ? "PASS" : "FAIL")}");
        Console.WriteLine();
    }

    static void TestCase2(Solution solution) 
    {
        int num1 = 5, num2 = 7;
        int expected = -1;
        int actual = solution.MakeTheIntegerZero(num1, num2);
        
        Console.WriteLine("Test 2:");
        Console.WriteLine($"Input: num1 = {num1}, num2 = {num2}");
        Console.WriteLine($"Expected: {expected}");
        Console.WriteLine($"Actual: {actual}");
        Console.WriteLine($"Result: {(actual == expected ? "PASS" : "FAIL")}");
        Console.WriteLine();
    }

}