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