動機
原來已經sort過了!!
Problem
Given an integer array nums
sorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order.
Example 1:
Input: nums = [-4,-1,0,3,10]Output: [0,1,9,16,100]Explanation: After squaring, the array becomes [16,1,0,9,100].After sorting, it becomes [0,1,9,16,100].
Example 2:
Input: nums = [-7,-3,2,3,11]Output: [4,9,9,49,121]
Constraints:
1 <= nums.length <= 104
-104 <= nums[i] <= 104
nums
is sorted in non-decreasing order.
Follow up: Squaring each element and sorting the new array is very trivial, could you find an
O(n)
solution using a different approach?Sol
這裡的重點是要從平方後最大的開始塞!!
class Solution:
def sortedSquares(self, nums: List[int]) -> List[int]:
ret = []
i,j = 0,len(nums)-1
while i <= j:
if abs(nums[i]) < abs(nums[j]):
n = nums[j]
j -= 1
else:
n = nums[i]
i += 1
ret.append(n*n)
ret.reverse()
return ret