455. 分发饼干

class Solution {
public:int findContentChildren(vector<int>& g, vector<int>& s) {// 先排序sort(g.begin(), g.end());sort(s.begin(), s.end());int i = 0;int j = 0;while (i < g.size() && j < s.size()) {if (s[j] >= g[i]) {i++;j++;}else {j++;}}return i;}
};

376. 摆动序列

class Solution {
public:int wiggleMaxLength(vector<int>& nums) {// 贪心策略if (nums.size() <= 1) {return nums.size();}int curDiff = 0;int preDiff = 0;int res = 1;for (int i = 0; i<nums.size()-1; i++) {curDiff = nums[i+1]-nums[i];if ((preDiff >=0 && curDiff < 0) || (preDiff <= 0 && curDiff > 0)){res++;preDiff = curDiff;}}return res;}
};

53. 最大子数组和

class Solution {
public:int maxSubArray(vector<int>& nums) {// 贪心// int res = INT32_MIN;// int count = 0;// for (int i = 0; i<nums.size();i++) {//     count += nums[i];//     if (count > res)//         res = count;//     if (count < 0) {//         count = 0;//     }// }// 动态规划if (nums.size() == 0)return 0;vector<int> dp(nums.size(), 0);dp[0] = nums[0];int res = dp[0];for (int i = 1; i<nums.size(); i++) {dp[i] = max(dp[i-1] + nums[i],nums[i]);if(dp[i] > res)res = dp[i];}return res;}
};

122. 买卖股票的最佳时机 II

class Solution {
public:int maxProfit(vector<int>& prices) {// 贪心int res = 0;for (int i = 1; i<prices.size(); i++) {if (prices[i]-prices[i-1] > 0){res += prices[i] - prices[i-1];}}// 动态规划return res;}
};

55. 跳跃游戏

class Solution {
public:bool canJump(vector<int>& nums) {// 能覆盖的最远范围int cover = 0;if (nums.size() == 0)return true;// cover的妙用for (int i = 0; i <= cover; i++) {cover = max(cover, i + nums[i]);// 如果覆盖范围超过数组长度，直接返回if (cover >= nums.size()-1)return true;}return false;}
};

45. 跳跃游戏 II

class Solution {
public:int jump(vector<int>& nums) {// 还是贪心策略if (nums.size() == 1)return 0;int ans = 0;int curDistance = 0;int nextDisdance = 0;for (int i = 0; i < nums.size(); i++) {nextDisdance = max(nextDisdance, nums[i] + i);if (curDistance == i) {ans ++;curDistance = nextDisdance;if (nextDisdance >= nums.size()-1)break;}}return ans;}
};