34. Find First and Last Position of Element in Sorted Array

class Solution {
    // lo, hi, mid = lo + (hi - lo) / 2
    // findFirst() nums[mid] < target
    // findLast() nums[mid] > target 
    public int[] searchRange(int[] nums, int target) {
        int n = nums.length;
        int left = findFirst(nums, target, n);
        int right = findLast(nums, target, n);
        return new int[]{left, right};
    }
    
    private int findFirst(int[] nums, int target, int n) {
        int lo = 0, hi = n - 1;
        int index = -1;
        while (lo <= hi) {
            int mid = lo + (hi - lo) / 2;
            if (nums[mid] < target) {
                lo = mid + 1;
            } else {
                hi = mid - 1;
            }
            
            if (nums[mid] == target) {
                index = mid;
            }
        }
        
        return index;
    }
    
    private int findLast(int[] nums, int target, int n) {
        int lo = 0, hi = n - 1;
        int index = -1;
        while (lo <= hi) {
            int mid = lo + (hi - lo) / 2;
            if (nums[mid] > target) {
                hi = mid - 1;
            } else {
                lo = mid + 1;
            }
            
            if (nums[mid] == target) {
                index = mid;
            }
        }
        
        return index;
    }
}