title
Given a sorted (in ascending order) integer array nums of n elements and a target value, write a function to search target in nums. If target exists, then return its index, otherwise return -1.
Example 1:
Input: nums = [-1,0,3,5,9,12], target = 9
Output: 4
Explanation: 9 exists in nums and its index is 4
Example 2:
Input: nums = [-1,0,3,5,9,12], target = 2
Output: -1
Explanation: 2 does not exist in nums so return -1
Note:
- You may assume that all elements in nums are unique.
- n will be in the range [1, 10000].
- The value of each element in nums will be in the range [-9999, 9999].
solution
class Solution {
public:
int search(vector<int>& nums, int target) {
if(nums.size()==0) return 0;
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){
l=mid+1;
}else{
r=mid-1;
}
}
return -1;
}
};