把一个数组最开始的若干个元素搬到数组的末尾,我们称之为数组的旋转。输入一个非减排序的数组的一个旋转,输出旋转数组的最小元素。例如数组{3,4,5,1,2}为{1,2,3,4,5}的一个旋转,该数组的最小值为1。
Note: 给出的所有元素都大于0,若数组大小为0,请返回0.
方法一:
# -*- coding:utf-8 -*-
# 复杂度 O(n)
class Solution:
def minNumberInRotateArray(self, rotateArray):
minNum = 0
for i in range(0, len(rotateArray)):
minNum = minNum if minNum < rotateArray[i] and minNum != 0 else rotateArray[i]
return minNum
if __name__ == '__main__':
s = Solution()
print(s.minNumberInRotateArray([3, 4, 5, 6, 7, 8, 1, 2]))
运行结果为:
1
方法二:
class Solution:
def minNumberInRotate(self, rotateArray):
# 最小值一定比前面的要小
# 二分查找数据,找左右的方法是:右边的值大于终止,就说明最小值在左边
if not rotateArray:
return 0
left = 0
right = len(rotateArray) - 1
while left <= right:
mid = (left + right) >> 1
if rotateArray[mid] < rotateArray[mid - 1]:
return rotateArray[mid]
elif rotateArray[mid] < rotateArray[right]:
right = mid - 1
else:
left = mid + 1
return 0
if __name__ == '__main__':
s = Solution()
print(s.minNumberInRotate([3, 4, 5, 6, 7, 8, 1, 2]))
运行结果为:
1