219. Contains Duplicate II
摘要：
Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and t...
Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the absolute difference between i and j is at most 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
難度：easy
題目：給定一整數陣列和一整數K,找出是否存在兩個不同的下標使用得nums[i]=nums[j]並且i與j之差的絕對值小於等於k.
思路：hashmap
Runtime: 9 ms, faster than 81.45% of Java online submissions for Contains Duplicate II.
Memory Usage: 41 MB, less than 77.21% of Java online submissions for Contains Duplicate II.
public class Solution {
public boolean containsNearbyDuplicate(int[] nums, int k) {
Map<Integer, Integer> mii = new HashMap<>();
for (int i = 0; i < nums.length; i++) {
if (mii.containsKey(nums[i]) && i - mii.get(nums[i]) <= k) {
return true;
}
mii.put(nums[i], i);
}
return false;
}
}