代码随想录算法训练营第32天| 122. 买卖股票的最佳时机 II、55. 跳跃游戏

122. 买卖股票的最佳时机 II：

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代码思路

prices = [7,1,5,3,6,4]，相邻两个元素只要是大于0，把大于0价差加起来就ok。因为只是问利润，但这并不是具体买卖过程。

class Solution:
    def maxProfit(self, prices: List[int]) -> int:
        profit = 0
        for i in range(1, len(prices)):
            diff = prices[i] - prices[i-1]
            if diff > 0:
                profit += diff
        return profit

55. 跳跃游戏：

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代码思路

class Solution:
    def canJump(self, nums: List[int]) -> bool:
        max_dist = 0
        for i in range(len(nums)):
            move = i + nums[i]
            if move > max_dist:
                max_dist = move
            if max_dist >= len(nums) - 1:
                return True
            if nums[i] == 0 and max_dist == i:
                return False
        return False

45. 跳跃游戏 II：

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代码思路

class Solution:
    def jump(self, nums: List[int]) -> int:
        n = len(nums)
        maxPos, end, step = 0, 0, 0
        for i in range(n - 1):
            if maxPos >= i:
                maxPos = max(maxPos, i + nums[i])
                if i == end:
                    end = maxPos
                    step += 1
        return step