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53 lines
1.4 KiB
Python
53 lines
1.4 KiB
Python
"""
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207. Course Schedule
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Difficulty: Medium
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https://leetcode.com/problems/course-schedule/
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──────────────────────────────────────────────────
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There are a total of numCourses courses you have to take, labeled
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from 0 to numCourses - 1. You are given an array prerequisites where
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prerequisites[i] = [ai, bi] indicates that you must take course bi
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first if you want to take course ai.
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• For example, the pair [0, 1], indicates that to take course 0 you
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have to first take course 1.
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Return true if you can finish all courses. Otherwise, return false.
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Example 1:
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Input: numCourses = 2, prerequisites = [[1,0]]
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Output: true
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Explanation: There are a total of 2 courses to take.
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To take course 1 you should have finished course 0. So it is possible.
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Example 2:
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Input: numCourses = 2, prerequisites = [[1,0],[0,1]]
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Output: false
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Explanation: There are a total of 2 courses to take.
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To take course 1 you should have finished course 0, and to take
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course 0 you should also have finished course 1. So it is impossible.
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Constraints:
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• 1 <= numCourses <= 2000
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• 0 <= prerequisites.length <= 5000
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• prerequisites[i].length == 2
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• 0 <= ai, bi < numCourses
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• All the pairs prerequisites[i] are unique.
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"""
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class Solution:
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def canFinish(self, numCourses: int, prerequisites: list[list[int]]) -> bool:
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