219. Contains Duplicate II

难度: Easy

题目描述

Given an integer array nums and an integer k, return true if there are two distinct indicesi and j in the array such that nums[i] == nums[j] and abs(i - j) <= k.

 

Example 1:

Input: nums = [1,2,3,1], k = 3
Output: true

Example 2:

Input: nums = [1,0,1,1], k = 1
Output: true

Example 3:

Input: nums = [1,2,3,1,2,3], k = 2
Output: false

 

Constraints:

• 1 <= nums.length <= 105
• -109 <= nums[i] <= 109
• 0 <= k <= 105

解题思路

代码实现

解决方案

java

func containsNearbyDuplicate(nums []int, k int) bool {

	m := make(map[int]int)

	for i := 0; i < len(nums); i++ {
		if pre, ok := m[nums[i]]; ok {
			if i-pre <= k {
				return true
			}
		}
		m[nums[i]] = i
	}

	return false

}