755. 倒水

https://leetcode-cn.com/problems/pour-water/

解法一：

注意只有当i-1比i处低的时候，水才能从i向左流入i-1，若相等是不流动的，因此要找到左侧最低处，只能用heights[left-1] <= heights[left]条件向左搜索（若去掉等号，则只能检测到严格递减的情况，而阶梯平台状的情况会漏掉），而要确定能否流动，要heights[left-1] < heights[left]条件

class Solution:
    def pourWater(self, heights: List[int], V: int, K: int) -> List[int]:
        n = len(heights)
        for i in range(V):
            left = best = K     #best记录最佳位置
            #先向左找
            while left-1 >= 0 and heights[left-1] <= heights[left]:
                if heights[left-1] < heights[left]:
                    best = left-1
                left -= 1
            if best != K:   #若找到
                heights[best] += 1
            else:   #若没找到则向右
                right = K
                while right+1 < n and heights[right+1] <= heights[right]:
                    if heights[right+1] < heights[right]:
                        best = right+1
                    right += 1
                heights[best] += 1
        return heights