alicode45-最活跃的数

package solution45;
import java.util.*;
class Solution {
    public int solution(int n, int[] nums) {
        HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();
        int maxVal = 0;
        for (int i = 0; i < n; i++) {
            int cur = nums[i];
            for (int j = -1; j <= 1; j++) {
                int val = cur + j;
                if (!map.containsKey(val)) {
                    map.put(val, 1);
                    maxVal = Math.max(maxVal, 1);
                } else {
                    int newval = map.get(val) + 1;
                    map.put(val, newval);
                    maxVal = Math.max(maxVal, newval);
                }
            }
        }
        return maxVal;
    }
}

算法思路：hash。