Here is the Code:
public int Search(int[] nums, int target) {
int s=0;
int e=nums.Length-1;
while(s<=e)
{
int mid = (s+e)/2;
if(nums[mid]==target)
{
return mid;
}
else if(target<nums[mid])
{
e=mid-1;
}
else
{
s=mid+1;
}
}
return -1;
}