Leetcode 985. Sum of Even Numbers After Queries

Posted 2021-09-01 SnailTyan

文章作者：Tyan
博客：noahsnail.com  |  CSDN  |  简书

1. Description

2. Solution

**解析：**Version 1，先对数组所有偶数求和，然后遍历查询，根据对应位置数字的奇偶性以及所加数字的奇偶性，来进行总和的加减操作并保存，最后需要更新对应位置的数值。

• Version 1

class Solution:
    def sumEvenAfterQueries(self, nums: List[int], queries: List[List[int]]) -> List[int]:
        total = 0
        result = []
        for i in range(len(nums)):
            if nums[i] % 2 == 0:
                total += nums[i]
        for val, index in queries:
            if nums[index] % 2 == 0:
                if val % 2 == 0:
                    total += val
                else:
                    total -= nums[index]
            elif val % 2 == 1:
                    total += nums[index] + val
            result.append(total)
            nums[index] = nums[index] + val
        return result

Reference

1. https://leetcode.com/problems/sum-of-even-numbers-after-queries/