题目链接：747. 至少是其他数字两倍的最大数
遍历一遍即可。
from typing import List
class Solution:
def dominantIndex(self, nums: List[int]) -> int:
if len(nums) == 1:
return 0
maxn, maxn2, maxn_idx = float('-inf'), float('-inf'), -1
for i, num in enumerate(nums):
if num > maxn:
maxn, maxn2, maxn_idx = num, maxn, i
elif num > maxn2:
maxn2 = num
if maxn >= 2 * maxn2:
return maxn_idx
return -1