1144.Decrease Elements To Make Array Zigzag

Given an array nums of integers, a move consists of choosing any element and decreasing it by 1.

An array A is a zigzag array if either:

Every even-indexed element is greater than adjacent elements, ie. A[0] > A[1] < A[2] > A[3] < A[4] > ...
OR, every odd-indexed element is greater than adjacent elements, ie. A[0] < A[1] > A[2] < A[3] > A[4] < ...

Return the minimum number of moves to transform the given array nums into a zigzag array.

Example 1:

Input: nums = [1,2,3]
Output: 2
Explanation: We can decrease 2 to 0 or 3 to 1.

Example 2:

Input: nums = [9,6,1,6,2]
Output: 4

class Solution(object):
    def movesToMakeZigzag(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        '''题意理解错误
        我一开始的理解是以为理解一次操作（就是比如2 to 0）代表两次的moves
        这样的话我的思路就变成一个寻找'''
        # def peak(a,b,c):
        #     if a < b and b > c and a!=c:
        #         return 0
        #     else:
        #         return 
        # def valley(a,b,c):
        #     if a > b and b < c and a!= c:
        #         return 0
        #     else:
        #         return 2
        # length = len(nums)
        # i = 0
        # '''even'''
        # while i < length -2:
        #     p = peak(nums[i-1],nums[i],nums[i+1])
        #     i += 1
        #     v = valley(nums[i-1],nums[i],nums[i+1])
        #     i += 1
        # print(p,v,1111)
        # return (p+v)

APPROACH ONE

'''copy lee215'''
def movesToMakeZigzag(self, nums):
    A = [float("inf")] + nums + [float("inf")]
    res = [0,0]
    for i in xrange(1,len(A)-1):
        res[i%2] += max(0,A[i]-min(A[i-1],A[i+1])+1)
    return min(res)

自己分析

from your python code , i learn that

the comparison among adjacent element and the pivot in elements
how to count even and odd in a array respectively

1144