You are given an integer array nums where the largest integer is unique.
Determine whether the largest element in the array is at least twice as much as every other number in the array. If it is, return the index of the largest element, or return -1 otherwise.
Example 1:
Input: nums = [3,6,1,0] Output: 1 Explanation: 6 is the largest integer. For every other number in the array x, 6 is at least twice as big as x. The index of value 6 is 1, so we return 1.
Example 2:
Input: nums = [1,2,3,4] Output: -1 Explanation: 4 is less than twice the value of 3, so we return -1.
Constraints:
2 <= nums.length <= 500 <= nums[i] <= 100- The largest element in
numsis unique.
class Solution:
def dominantIndex(self, nums: List[int]) -> int:
max_num =max(nums)
index = nums.index(max_num)
nums.remove(max_num)
if max_num >= max(nums)*2:
return index
return -1
# # another approach: find max & 2nd max, them check if max >= 2*end Max
# f_max = nums[0]
# s_max = None
# max_index = 0
# for i, num in enumerate(nums[1:]):
# if num > f_max:
# s_max = f_max
# f_max = num
# max_index = i+1
# elif not s_max or num > s_max:
# s_max = num
# # print(f_max, s_max, max_index)
# return max_index if f_max >= 2*s_max else -1