算法训练Day28 | ● 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<int>& prices) {vector<int> dp(2,0);dp[0] = -prices[0];for(int i=1; i<prices.size(); i++){dp[0] = max(dp[0], dp[1]-prices[i]);dp[1] = max(dp[1], prices[i]+dp[0]);}return dp[1];}
};

参考文章：代码随想录- 122.买卖股票的最佳时机II

55. 跳跃游戏

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

参考文章：代码随想录-55. 跳跃游戏

45.跳跃游戏II

class Solution {
public:int jump(vector<int>& nums) {if (nums.size() == 1) return 0;int cover = 0;int next_cover = 0;int count = 0;for(int i=0; i<=nums.size(); i++){if(i+nums[i]>next_cover){next_cover = i+nums[i];}if(i == cover){count++;cover = next_cover;if(next_cover>=nums.size()-1){return count;}}}return -1;}
};

参考文章：代码随想录- 45.跳跃游戏II