力扣剑指offer2第23天二分查找

68) 查找插入位置

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

69) 山峰数组的顶部

class Solution{
public:
    int peakIndexInMountainArray(vector& arr){
        int l=1, r=arr.size()-2, mid=1;
        while(l<=r){
            mid = (l+r)/2;
            if(arr[mid]>arr[mid-1] && arr[mid]>arr[mid+1]) break;
            if(arr[mid]>arr[mid-1] && arr[mid]

70）排序数组中只出现一次的数字

class Solution{
public:
    int singleNonDuplicate(vector& nums){
        int l=0, r=nums.size()-1;
        while(l