MediumNo. 1010
Pairs of Songs With Total Durations Divisible by 60 — LeetCode 1010 Python Solution
- Pattern
- Hash Map
- Topics
- Array, Hash Table, Counting
- Reading time
- 2 min
- Source
- leetcode.com
The problem
You are given a list of songs where the ith song has a duration of time[i] seconds. Return the number of pairs of songs for which their total duration in seconds is divisible by 60.
Example
- Input
- time = [30,20,150,100,40]
- Output
- 3
- Explanation
- Three pairs have a total duration divisible by 60:
Python solution
class Solution:
def numPairsDivisibleBy60(self, time: List[int]) -> int:
cnt = Counter(t % 60 for t in time)
ans = sum(cnt[x] * cnt[60 - x] for x in range(1, 30))
ans += cnt[0] * (cnt[0] - 1) // 2
ans += cnt[30] * (cnt[30] - 1) // 2
return ansComplexity
- Time
- O(n)
- Space · auxiliary
- O(n)
Pattern: Hash Map
Trade memory for time: remember what you have seen so the second pass never happens. LeetCode 1010. Pairs of Songs With Total Durations Divisible by 60 is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Hash Table and Counting.
The hash map guide has the Python template for the pattern and the 709 LeetCode problems that use it.
Related problems
| No. | Problem | Difficulty |
|---|---|---|
| 0169 | Majority Element | Easy |
| 0229 | Majority Element II | Medium |
| 0347 | Top K Frequent Elements | Medium |
| 0594 | Longest Harmonious Subsequence | Easy |
| 0621 | Task Scheduler | Medium |
| 0692 | Top K Frequent Words | Medium |
Frequently asked questions
- How hard is LeetCode 1010. Pairs of Songs With Total Durations Divisible by 60?
LeetCode 1010. Pairs of Songs With Total Durations Divisible by 60 is rated Medium on LeetCode.
- What is the time complexity of LeetCode 1010. Pairs of Songs With Total Durations Divisible by 60?
The Python solution on this page runs in O(n).
- What is the space complexity of LeetCode 1010. Pairs of Songs With Total Durations Divisible by 60?
The Python solution on this page uses O(n) auxiliary space.
- What topics does LeetCode 1010. Pairs of Songs With Total Durations Divisible by 60 cover?
LeetCode 1010. Pairs of Songs With Total Durations Divisible by 60 is tagged Array, Hash Table and Counting on LeetCode.