35题

方法：二分搜索

class Solution {
public:
    int searchInsert(vector<int>& nums, int target) {
        return dfs(nums,target,0,nums.size()-1);
    }
    int dfs(vector<int>& nums, int target,int left,int right){
        int a;
        if(left==right){
            if(nums[left]<target){
                return left+1;
            }else{
                return left;
            }
        }
        int mid=left+(right-left)/2;
        if(nums[mid]<target){
            a=dfs(nums,target,mid+1,right);
        }
        else if(nums[mid]>target){
            a=dfs(nums,target,left,mid);
        }else{
            return mid;
        }
        return a;
    }
};