递归解法

class Solution {
public:int search(vector<int>& nums, int target) {return midsearch(nums,target,0,nums.size()-1);}int midsearch(vector<int>& nums, int target, int low,int high){if(low <= high){int mid = (low+high) / 2;if(nums[mid]<target) return midsearch(nums,target,mid+1,high);if(nums[mid]>target) return midsearch(nums,target,low,mid-1);if(nums[mid] == target) return mid;}return -1;}
};

class Solution {
public:int search(vector<int>& nums, int target) {int low = 0;int high = nums.size()-1;while(low<=high){int mid = (low+high) / 2;if(nums[mid] == target) return mid;else if(nums[mid] > target) high = mid - 1;else low = mid + 1;}return -1;}
};

class Solution {
public:bool isAnagram(string s, string t) {int n1 = s.size();int n2 = t.size();if(n1!=n2) return false;quicksort(s,0,n1-1);quicksort(t,0,n2-1);if(s==t) return true;return false;}int partition(string &s ,int low,int high){char c = s[low];while(low<high){while(low<high && s[high] >= c) high--;s[low] = s[high];while(low<high && s[low] <= c) low++;s[high] = s[low];}s[low] = c;return low;}void quicksort(string &s,int low,int high){if(low < high){int p = partition(s,low,high);quicksort(s,low,p-1);quicksort(s,p+1,high);}}
};

顺便练习一下快排