public int bigDiff(int[] nums) {
  int largest = nums[0];
  int smallest = nums[0];
  for (int n : nums) {
    largest = Math.max(largest, n);
    smallest = Math.min(smallest, n);
  }
  return largest - smallest;
}

public int bigDiff(int[] nums) {
  int largest = nums[0];
  int smallest = nums[0];
  for (int n : nums) {
    if (n > largest) {
      largest = n;
    }
    else if (n < smallest) {
      smallest = n;
    }
  }
  return largest - smallest;
}