2670. 找出不同元素数目差数组

2670. 找出不同元素数目差数组

• 难度: easy
• 原始链接: https://leetcode.cn/problems/find-the-distinct-difference-array
• 标签: 哈希

解法一: 哈希

go

func distinctDifferenceArray(nums []int) []int {
  leftCount := make(map[int]int)
  rightCount := make(map[int]int)
  for _, num := range nums {
    rightCount[num]++
  }
  n := len(nums)
  ans := make([]int, n)
  for i, num := range nums {
    rightCount[num]--
    if rightCount[num] == 0 {
      delete(rightCount, num)
    }
    leftCount[num]++
    ans[i] = len(leftCount) - len(rightCount)
  }
  return ans
}