35. Search Insert Position

Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.

You may assume no duplicates in the array.

Here are few examples.

[1,3,5,6], 5 → 2

[1,3,5,6], 2 → 1

[1,3,5,6], 7 → 4

[1,3,5,6], 0 → 0

这道题就是用二分查找就行了

#include<iostream>
#include<vector>
using namespace std;
class Solution {
public:
int searchInsert(vector<int>& nums, int target)
{
int l=0,r=nums.size()-1,mid;
while(l<r)
{
mid=(l+r)/2;
if(nums[mid]==target)
return mid;
else if(nums[mid]>target)
r=mid-1;
else
l=mid+1;
}
if(nums[l]==target)
return l;
else if(nums[l]<target)
return l+1;
else
return l==0?0:l;
}
};
int main()
{
vector<int>number;
int N,i,temp;
cin>>N;
for(i=0;i<N;i++)
{
cin>>temp;
number.push_back(temp);
}
int target;
cin>>target;
Solution solve;
cout<<solve.searchInsert(number,target);
return 0;
}