思路：计算每天的利润，利润如果为正，加到结果中去

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

class Solution {
private:int cover =0;
public:bool canJump(vector<int>& nums) {if(nums.size()==1) return true;//一个元素直接返回truefor(int i =0;i<=cover;i++){cover = max(i+nums[i],cover); //动态更新覆盖范围if(cover>=nums.size()-1) return true;}return false;}
};

class Solution {
public:int jump(vector<int>& nums) {int curDistance = 0;    // 当前覆盖的最远距离下标int ans = 0;            // 记录走的最大步数int nextDistance = 0;   // 下一步覆盖的最远距离下标for (int i = 0; i < nums.size() - 1; i++) { // 注意这里是小于nums.size() - 1，这是关键所在nextDistance = max(nums[i] + i, nextDistance); // 更新下一步覆盖的最远距离下标if (i == curDistance) {                 // 遇到当前覆盖的最远距离下标curDistance = nextDistance;         // 更新当前覆盖的最远距离下标ans++;}}return ans;}
};