2026.02.11

860. 柠檬水找零

class Solution:
    def lemonadeChange(self, bills: List[int]) -> bool:
        cash = [0] * 11
        for i in range(len(bills)):
            if bills[i] == 5:
                cash[5] += 1
            elif bills[i] == 10:
                cash[5] -= 1
                if cash[5] < 0:
                    return False
                cash[10] += 1
            else:
                if cash[10] > 0 and cash[5] > 0:
                    cash[10] -= 1
                    cash[5] -= 1
                elif cash[5] >= 3:
                    cash[5] -= 3
                else:
                    return False
        return True

406. 根据身高重建队列

class Solution:
    def reconstructQueue(self, people: List[List[int]]) -> List[List[int]]:
        people.sort(key = lambda x: (-x[0], x[1]))

        que = []
        for p in people:
            que.insert(p[1], p)
        return que

452. 用最少数量的箭引爆气球

class Solution:
    def findMinArrowShots(self, points: List[List[int]]) -> int:
        points.sort(key = lambda x : x[1])
        count = 0
        ed = float('-inf')
        for p in points:
            if ed < p[0]:
                count += 1
                ed = p[1]
                
        return count