219. 存在重复元素 II

 

 

class Solution {
    public boolean containsNearbyDuplicate(int[] nums, int k) {
        Map map = new HashMap();
        int length = nums.length;
        for (int i = 0; i < length; i++) {
            int num = nums[i];
            if (map.containsKey(num) && i - map.get(num) <= k) {
                return true;
            }
            map.put(num, i);
        }
        return false;
    }
}