2169. Count Operations to Obtain Zero #

Problem #

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 <= 10^5

Problem Summary #

You are given two non-negative integers num1 and num2. In each operation, if num1 >= num2, you must subtract num2 from num1; otherwise, you must subtract num1 from num2.

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

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

Solution Approach #

• Simple problem. Simulate according to the problem statement: subtract the two numbers each time and accumulate the operation count. When one number becomes 0, output the operation count.

Code #

package leetcode

func countOperations(num1 int, num2 int) int {
	res := 0
	for num1 != 0 && num2 != 0 {
		if num1 >= num2 {
			num1 -= num2
		} else {
			num2 -= num1
		}
		res++
	}
	return res
}