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 45.跳跃游戏II

122.买卖股票的最佳时机II

class Solution {
public:
    int maxProfit(vector& prices) {
        int result = 0;
        for (int i = 1; i < prices.size(); i++) {
            result += max(prices[i] - prices[i - 1], 0);
        }
        return result;
    }
};

 思路太重要了

图片来源：转载自代码随想录

55. 跳跃游戏

class Solution {
public:
    bool canJump(vector& nums) {
        int cover = 0;
        if (nums.size() == 1) return true;
        for (int i = 0; i <= cover; i++) {
            cover = max(cover, i + nums[i]);
            if (cover >= nums.size() - 1) return true;
        }
        return false;
    }
};

45.跳跃游戏II

class Solution {
public:
    int jump(vector& nums) {
        if (nums.size() == 1) return 0;
        int cur = 0;
        int next = 0;
        int res = 0;
        for (int i = 0; i < nums.size(); i++) {
            next = max(next, nums[i] + i);
            if (i == cur) {
                res++;
                cur = next;
                if (next >= nums.size() - 1) break;
            }
        }
        return res;
    }
};