12. 그리디 알고리즘(탐욕법)

개미 군단 - https://school.programmers.co.kr/tryouts/85949/challenges

def solution(hp):
    x1, r = hp//5, hp%5
    x2, r = r//3, r%3
    x3 = r//1
    return x1+x2+x3

 

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체육복 - https://school.programmers.co.kr/tryouts/85950/challenges

def solution(n, lost, reserve):
    lost, reserve = set(lost), set(reserve)
    real_lost = lost - reserve
    real_reserve = reserve-lost
    cur_sum = n - len(real_lost)
    for cur_num in real_lost:
        if cur_num - 1 in real_reserve:
            cur_sum += 1
            real_reserve.remove(cur_num-1)
        elif cur_num + 1 in real_reserve:
            cur_sum += 1
            real_reserve.remove(cur_num+1)
    return cur_sum

 

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단속카메라 - https://school.programmers.co.kr/tryouts/85951/challenges

def solution(routes):
    routes.sort(key=lambda x:(x[1]))  
    camera = routes[0][1]
    ans = 1
    for route in routes:
        if route[0] > camera:
            ans += 1
            camera = route[1]
    return ans