0. 差分数组的概念:
常用于某个区间值都需加/减去a的问题。
1. 1094拼车

class Solution:
def carPooling(self, trips: List[List[int]], capacity: int) -> bool:
max_val = 0
for i in range(len(trips)):
max_val = max(max_val, trips[i][2])
diff = [0]*(max_val+2)
for i in range(len(trips)):
diff[trips[i][1