뒤에 있는 큰 수 찾기

https://school.programmers.co.kr/learn/courses/30/lessons/154539

def solution(numbers):
    answer = []
    for i in range(len(numbers)):
        for j in range(i + 1, len(numbers)):
            if numbers[j] > numbers[i]:
                answer.append(numbers[j])
                break
        else:
            answer.append(-1)
    return answer

뭐 당연히 이런 코드로는 통과 불능... 
예전 Level 2의 수준과 다르게 어려워 졌다. ㅜ,.ㅜ

편법이지만 뒤집어 생각하면 통과는 가능하다. 

def solution(numbers):
    answer = [-1 for _ in numbers]
    for i in range(len(numbers) - 1, -1, -1):
        for j in range(i - 1, -1, -1):
            if numbers[j] >= numbers[i]:
                break
            answer[j] = numbers[i]
    return answer

힙을 써야한다. 

from heapq import heappop, heappush


def solution(numbers):
    answer = [-1 for _ in numbers]
    heap = []
    for i, each in enumerate(numbers):
        while heap and heap[0][0] < each:
            _, index = heappop(heap)
            answer[index] = each
        heappush(heap, (each, i))
    return answer