https://leetcode.cn/problems/search-insert-position/
简单二分，这里可以判断return，相当于剪枝
class Solution {
public:
int searchInsert(vector<int>& nums, int target) {
int l=0,r=nums.size()-1;
if(target>nums[r])return r+1;
while(l<r)
{
int mid=l+r>>1;
if(nums[mid]>=target)r=mid;
else l=mid+1;
}
return l;
}
};