面试经典 150 题：189、383

189. 轮转数组

【参考代码】

class Solution {
public:void rotate(vector<int>& nums, int k) {int size = nums.size();if(1 == size){return;}vector<int> temp(size);//k = k % size;for(int i=0; i<size; i++){temp[(i + k) % size] = nums[i];}nums = temp;  }
};

383. 赎金信

【参考代码】

class Solution {
public:bool canConstruct(string ransomNote, string magazine) {//子串是ransomNote，父串是magazine，判断父串是否包含子串int cnt[26] = {0};if(ransomNote.size() > magazine.size() || ransomNote.size() == 0){return false;}for(char c : magazine){cnt[c - 'a']++;}for(char c : ransomNote){cnt[c - 'a']--;if(cnt[c - 'a'] < 0)return false;}return true;}
};