Minimum Number of Operations to Convert Time — LeetCode 2224 Python Solution

The problem

You are given two strings current and correct representing two 24-hour times. 24-hour times are formatted as "HH:MM", where HH is between 00 and 23, and MM is between 00 and 59.

Example

Input

current = "02:30", correct = "04:35"

Output

3

Explanation

We can convert current to correct in 3 operations as follows:

Python solution

class Solution:
    def convertTime(self, current: str, correct: str) -> int:
        a = int(current[:2]) * 60 + int(current[3:])
        b = int(correct[:2]) * 60 + int(correct[3:])
        ans, d = 0, b - a
        for i in [60, 15, 5, 1]:
            ans += d // i
            d %= i
        return ans

Complexity

Pattern: Greedy

Take the locally best option every time — when you can prove that never costs you later. LeetCode 2224. Minimum Number of Operations to Convert Time is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Greedy.

The greedy guide has the Python template for the pattern and the 346 LeetCode problems that use it.

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