面试题 04.06. 后继者

面试题 04.06. 后继者

class Solution:
    def inorderSuccessor(self, root: TreeNode, p: TreeNode) -> Any | None:
        if root is None or p is None:
            return None
        node = root
        ans = None
        while node:
            if node.val <= p.val:
                node = node.right
            else:
                if ans is None or ans.val > node.val:
                    ans = node
                node = node.left
        return ans

LCR 088. 使用最小花费爬楼梯

LCR 088. 使用最小花费爬楼梯

class Solution:
    def minCostClimbingStairs(self, cost: List[int]) -> int:
        dp = [0 for i in range(len(cost))]
        dp[0], dp[1] = cost[0], cost[1]
        for i in range(2, len(cost)):
            dp[i] = min(cost[i] + dp[i - 1], cost[i] + dp[i - 2])
        return min(dp[-1], dp[-2])

2087. 网格图中机器人回家的最小代价

2087. 网格图中机器人回家的最小代价

class Solution:
    def minCost(self, startPos: List[int], homePos: List[int], rowCosts: List[int], colCosts: List[int]) -> int:
        row_diff = homePos[0] - startPos[0]
        col_diff = homePos[1] - startPos[1]
        now_pos = startPos
        cost = 0
        while now_pos != homePos:
            if row_diff > 0:
                cost += rowCosts[now_pos[0] + 1]
                now_pos[0] += 1
                row_diff -= 1
            elif row_diff < 0:
                cost += rowCosts[now_pos[0] - 1]
                now_pos[0] -= 1
                row_diff += 1

            if col_diff > 0:
                cost += colCosts[now_pos[1] + 1]
                now_pos[1] += 1
                col_diff -= 1
            elif col_diff < 0:
                cost += colCosts[now_pos[1] - 1]
                now_pos[1] -= 1
                col_diff += 1
        return cost

2055. 蜡烛之间的盘子

2055. 蜡烛之间的盘子

import bisect


class Solution:
    def platesBetweenCandles(self, s: str, queries: List[List[int]]) -> List[int]:
        candles_list = []
        for i in range(len(s)):
            if s[i] == '|':
                candles_list.append(i)
        answer = []
        for item in queries:
            start = item[0]
            end = item[1]
            start = bisect.bisect_left(candles_list, start)
            end = bisect.bisect_right(candles_list, end) - 1
            if end <= start:
                answer.append(0)
            else:
                answer.append(candles_list[end] - candles_list[start] - 1 - (end - start - 1))
        return answer