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].
public class Solution {
public int Search(int[] nums, int target) {
int low = 0;
int high = nums.Length-1;
while(low<=high){
int mid = low+(high-low)/2;
if(nums[mid]>target){
high = mid-1;
}
else if(nums[mid]<target){
low = mid + 1;
}
else if(nums[mid]==target){
return mid;
}
else{
return -1;
}
}
return -1;
}
}Time Complexity: O(logn)
Space Complexity: O(1)
