In a group of N people (labelled 0, 1, 2, ..., N-1), each person has different
amounts of money, and different levels of quietness.
For convenience, we'll call the person with label x, simply "person
x".
We'll say that richer[i] = [x, y] if person x definitely
has more money than person y. Note that richer may
only be a subset of valid observations.
Also, we'll say quiet[x] = q if person x has
quietness q.
Now, return answer, where answer[x] = y if y is the
least quiet person (that is, the person y with the smallest value of quiet[y]),
among all people who definitely have equal to or more money than person
x.
Example 1:
Input: richer = [[1,0],[2,1],[3,1],[3,7],[4,3],[5,3],[6,3]], quiet = [3,2,5,4,6,1,7,0] Output: [5,5,2,5,4,5,6,7] Explanation: answer[0] = 5. Person 5 has more money than 3, which has more money than 1, which has more money than 0. The only person who is quieter (has lower quiet[x]) is person 7, but it isn't clear if they have more money than person 0. answer[7] = 7. Among all people that definitely have equal to or more money than person 7 (which could be persons 3, 4, 5, 6, or 7), the person who is the quietest (has lower quiet[x]) is person 7. The other answers can be filled out with similar reasoning.