2545. Sort the Students by Their Kth Score

Problem

There is a class with m students and n exams. You are given a 0-indexed m x n integer matrix score, where each row represents one student and score[i][j] denotes the score the iᵗʰ student got in the jᵗʰ exam. The matrix score contains distinct integers only.

You are also given an integer k. Sort the students (i.e., the rows of the matrix) by their scores in the kᵗʰ (0-indexed) exam from the highest to the lowest.

Return the matrix after sorting it.

https://leetcode.cn/problems/sort-the-students-by-their-kth-score/

Example 1:

Input: score = [[10,6,9,1],[7,5,11,2],[4,8,3,15]], k = 2
Output: [[7,5,11,2],[10,6,9,1],[4,8,3,15]]
Explanation: In the above diagram, S denotes the student, while E denotes the exam.

• The student with index 1 scored 11 in exam 2, which is the highest score, so they got first place.
• The student with index 0 scored 9 in exam 2, which is the second highest score, so they got second place.
• The student with index 2 scored 3 in exam 2, which is the lowest score, so they got third place.

Example 2:

Input: score = [[3,4],[5,6]], k = 0
Output: [[5,6],[3,4]]
Explanation: In the above diagram, S denotes the student, while E denotes the exam.

• The student with index 1 scored 5 in exam 0, which is the highest score, so they got first place.
• The student with index 0 scored 3 in exam 0, which is the lowest score, so they got second place.

Constraints:

• m == score.length
• n == score[i].length
• 1 <= m, n <= 250
• 1 <= score[i][j] <= 10⁵
• score consists of distinct integers.
• 0 <= k < n

Test Cases

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class Solution:
    def sortTheStudents(self, score: List[List[int]], k: int) -> List[List[int]]:

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import pytest

from solution import Solution


@pytest.mark.parametrize('score, k, expected', [
    ([[10,6,9,1],[7,5,11,2],[4,8,3,15]], 2, [[7,5,11,2],[10,6,9,1],[4,8,3,15]]),
    ([[3,4],[5,6]], 0, [[5,6],[3,4]]),
])
@pytest.mark.parametrize('sol', [Solution()])
def test_solution(sol, score, k, expected):
    assert sol.sortTheStudents(score.copy(), k) == expected

Thoughts

这题用 Python 实现是不是某种程度上的「作弊」呢……

Code

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class Solution:
    def sortTheStudents(self, score: list[list[int]], k: int) -> list[list[int]]:
        score.sort(key=lambda row: row[k], reverse=True)
        return score

许可协议

本文除了题目描述（Problem）部分之外，其他内容由 Calf 原创，采用 CC BY-NC-SA 4.0 许可协议，转载请注明出处。

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