2169

2169. Count Operations to Obtain Zero (Easy)

You are given two non-negative integers num1 and num2.

In one operation, if num1 >= num2, you must subtract num2 from num1, otherwise subtract num1 from num2.

• For example, if num1 = 5 and num2 = 4, subtract num2 from num1, thus obtaining num1 = 1 and num2 = 4. However, if num1 = 4 and num2 = 5, after one operation, num1 = 4 and num2 = 1.

Return the number of operations required to make either num1 = 0 or num2 = 0.

 

Example 1:

Input: num1 = 2, num2 = 3
Output: 3
Explanation: 
- Operation 1: num1 = 2, num2 = 3. Since num1 < num2, we subtract num1 from num2 and get num1 = 2, num2 = 3 - 2 = 1.
- Operation 2: num1 = 2, num2 = 1. Since num1 > num2, we subtract num2 from num1.
- Operation 3: num1 = 1, num2 = 1. Since num1 == num2, we subtract num2 from num1.
Now num1 = 0 and num2 = 1. Since num1 == 0, we do not need to perform any further operations.
So the total number of operations required is 3.

Example 2:

Input: num1 = 10, num2 = 10
Output: 1
Explanation: 
- Operation 1: num1 = 10, num2 = 10. Since num1 == num2, we subtract num2 from num1 and get num1 = 10 - 10 = 0.
Now num1 = 0 and num2 = 10. Since num1 == 0, we are done.
So the total number of operations required is 1.

 

Constraints:

• 0 <= num1, num2 <= 105

Similar Questions:

• Number of Steps to Reduce a Number to Zero (Easy)

Solution 1.

// OJ: https://leetcode.com/problems/count-operations-to-obtain-zero/
// Author: github.com/lzl124631x
// Time: O(max(num1, num2))
// Space: O(1)
class Solution {
public:
    int countOperations(int num1, int num2) {
        int ans = 0;
        for (; num1 && num2; ++ans) {
            if (num1 >= num2) num1 -= num2;
            else num2 -= num1;
        }
        return ans;
    }
};

Solution 2.

// OJ: https://leetcode.com/problems/count-operations-to-obtain-zero/
// Author: github.com/lzl124631x
// Time: O(max(num1, num2))
// Space: O(1)
class Solution {
public:
    int countOperations(int num1, int num2) {
        int ans = 0;
        while (num1 && num2) {
            if (num1 >= num2) ans += num1 / num2, num1 %= num2;
            else ans += num2 / num1, num2 %= num1;
        }
        return ans;
    }
};

Discuss

https://leetcode.com/problems/count-operations-to-obtain-zero/discuss/1766767