Statement
You are given an integer, num_courses, representing the total number of courses you need to complete, labeled from 0 to num_courses - 1.
You are also given a prerequisites array, where prerequisites[i] = [a[i], b[i]] indicates that you must take course b[i] first if you want to take the course a[i]. For example, the pair indicates that to take course , you have to first take course .
Return TRUE if all of the courses can be finished. Otherwise, return FALSE.
Constraints:
-
num_courses -
prerequisites.length prerequisites[i].length-
a[i],b[i]num_courses - All the pairs
prerequisites[i]are unique.