alicode45-最活跃的数

 1 package solution45;
 2 import java.util.*;
 3 class Solution {
 4     public int solution(int n, int[] nums) {
 5         HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();
 6         int maxVal = 0;
 7         for (int i = 0; i < n; i++) {
 8             int cur = nums[i];
 9             for (int j = -1; j <= 1; j++) {
10                 int val = cur + j;
11                 if (!map.containsKey(val)) {
12                     map.put(val, 1);
13                     maxVal = Math.max(maxVal, 1);
14                 } else {
15                     int newval = map.get(val) + 1;
16                     map.put(val, newval);
17                     maxVal = Math.max(maxVal, newval);
18                 }
19             }
20         }
21         return maxVal;
22     }
23 }

算法思路：hash。

来源：https://www.cnblogs.com/asenyang/p/12432422.html