描述
给出一个整数数组 nums 和一个整数 k。划分数组(即移动数组 nums 中的元素),使得:
所有小于k的元素移到左边
所有大于等于k的元素移到右边
返回数组划分的位置,即数组中第一个位置 i,满足 nums[i] 大于等于 k。
python code
class Solution:
"""
@param nums: The integer array you should partition
@param k: As description
@return: The index after partition
"""
def partitionArray(self, nums, k):
# write your code here
# you should partition the nums by k
# and return the partition index as description
if len(nums) == 0:
return 0
else:
return self.position(nums, k, 0, len(nums) - 1)
def position(self, nums, k, start, end):
i = start
j = end
while i < j:
while i <= j and nums[j] >= k:
j -= 1
while i <= j and nums[i] < k:
i += 1
if i < j:
temp = nums[i]
nums[i] = nums[j]
nums[j] = temp
i += 1
j -= 1
return i
说明
注意 <= 和 < 的条件