# 300分！给一个数组 求里面出现次数最多的元素和其次数 另：需要加上时间复杂度，否则只给5分。最优算法给100分,该怎么处理

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300分！给一个数组 求里面出现次数最多的元素和其次数 另：需要加上时间复杂度，否则只给5分。最优算法给100分

Java code
```
int nums []=  { 2,4,3,6,9,2,1,9,3,7,4,1,0,1,2,2,1,5,8,8,4,1,1,7,6,1,9,6,5,5,6,9,1,8,7,9,9,1,6,3,4,4,6,5,3,1,1,5,7,7,8,0,1,9,3,5,2,4,4,4,0,8,5,3,2,1,9,6,7,9,8,2,6,4,1,7,2,0,9,1,4,6,6,5,5,6,3,5,3,3,8,3,6,3,1,0,6,2,7,1,8,4,7,3,3,1,3,1,3,7,4,0,9,7,9,4,6,0,2,1,9,2,8,8,0,1,6,4,4,4,0,4,4,3,3,4,9,3,0,3,5,6,3,2,4,7,5,1,3,7,4,4,4,8,5,7,9,8,7,1,3,1,0,7,8,4,6,9,5,2,8,5,2,7,3,8,4,4,6,3,5,9,2,8,9,8,7,1,6,5,1,4,4,1,5,8,7,5,9,0,7,4,6,5,3,6,1,2,9,6,2,1,1,8,4,1,2,6,6,0,0,4,9,0,8,9,5,7,7,2,3,8,4,2,7,8,7,5,3,4,4,6,9,5,0,4,8,7,1,6,3,1,9,7,4,9,0,4,0,3,5,8,0,8,6,7,8,1,0,2,0,8,3,0,1,1,7,6,6,2,2,8,1,7,8,2,5,2,5,8,4,0,0,2,4,2,8,3,4,2,5,6,4,4,8,8,7,2,3,8,0,0,6,4,2,1,6,7,1,5,3,7,1,2,3,4,5,1,8,1,5,1,3,1,8,5,1,0,1,1,8,4,6,2,6,8,0,2,7,4,3,0,8,5,0,1,2,8,1,2,9,0,4,8,5,5,8,1,5,8,9,5,2,9,8,2,2,0,2,6,1,9,0,5,8,4,6,9,1,6,8,0,7,0,3,5,5,9,5,9,9,6,1,9,2,8,2,7,6,8,0,8,7,1,4,2,2,7,6,1,7,0,9,7,6,4,4,3,3,5,7,7,8,9,6,9,6,3,7,6,3,2,5,2,5,8,2,7,1,0,7,7,5,6,8,9,2,3,4,9,6,1,3,9,1,9,0,5,6,7,0,7,6,0,5,3,7,4,5,0,2,1,1,8,2,4,8,4,5,4,8,2,2,6,1,7,0,9,3,1,5,4,0,4,2,9,4,5,4,7,7,0,2,1,7,5,3,5,6,0,7,3,6,5,9,5,4,4,1,6,5,6,1,1,4,2,1,9,7,4,6,3,6,9,1,3,4,0,1,8,1,5,0,3,4,9,3,1,7,8,2,2,2,2,5,1,4,0,2,2,2,1,2,9,9,8,2,9,6,0,4,9,5,2,1,3,7,0,2,5,8,5,0,2,7,0,2,6,2,4,7,6,1,2,3,5,7,5,6,2,1,5,0,2,1,2,3,4,7,8,3,8,0,8,2,5,5,8,0,1,3,3,7,5,9,8,8,1,5,0,5,4,1,9,2,1,0,9,1,0,6,7,8,4,9,7,9,0,0,8,2,5,1,7,0,7,5,8,5,9,6,6,6,3,1,5,0,8,3,0,3,4,8,4,3,3,9,3,0,7,8,9,3,4,5,6,0,9,7,2,1,1,8,4,6,0,3,4,7,4,6,7,9,3,0,3,9,6,9,2,2,2,5,5,9,0,0,6,2,4,1,1,7,6,3,9,5,6,6,6,8,8,1,2,0,4,3,0,9,4,5,4,9,1,7,7,2,1,1,0,0,0,9,3,3,1,9,3,3,7,3,7,1,2,2,6,0,4,8,9,0,7,8,3,8,3,4,1,2,8,1,6,0,1,2,1,9,2,8,3,2,5,8,5,9,3,2,1,6,9,7,6,5,3,0,1,4,4,2,8,4,4,2,0,9,0,7,7,7,6,4,0,6,9,2,4,7,2,3,9,9,8,3,8,3,8,1,3,6,9,8,5,8,1,4,2,0,2,9,4,2,7,6,1,9,6,3,0,4,1,8,1,3,4,5,2,0,5,5,3,8,0,9,0,1,3,4,8,1,5,0,9,6,5,0,7,2,8,2,3,2,9,9,2,4,7,0,8,6,4,0,8,6,8,3,6,6,7,5,3,0,1,3,7,1,6,3,8,4,5,4,1,2,9,0,5,7,1,7,1,2,9,3,8,1,2,7,5,3,8,7,1,7,3,0,8,2,9,6,8,6,0,9,9,5,4,3,8,1,2,2,2,2,3,9,8,5,5,5,5,2,9,8,8,1,3,0,1,1,9,3,7,7,7,2,2,3,6,3,7};

```

------解决方案--------------------
Java code
```
package CSDN;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class CountArray {
public static void main(String[] args) {
int nums[] = { 2, 4, 3, 6, 9, 2, 1, 9, 3, 7, 4, 1, 0, 1, 2, 2, 1, 5, 8,
8, 4, 1, 1, 7, 6, 1, 9, 6, 5, 5, 6, 9, 1, 8, 7, 9, 9, 1, 6, 3,
4, 4, 6, 5, 3, 1, 1, 5, 7, 7, 8, 0, 1, 9, 3, 5, 2, 4, 4, 4, 0,
8, 5, 3, 2, 1, 9, 6, 7, 9, 8, 2, 6, 4, 1, 7, 2, 0, 9, 1, 4, 6,
6, 5, 5, 6, 3, 5, 3, 3, 8, 3, 6, 3, 1, 0, 6, 2, 7, 1, 8, 4, 7,
3, 3, 1, 3, 1, 3, 7, 4, 0, 9, 7, 9, 4, 6, 0, 2, 1, 9, 2, 8, 8,
0, 1, 6, 4, 4, 4, 0, 4, 4, 3, 3, 4, 9, 3, 0, 3, 5, 6, 3, 2, 4,
7, 5, 1, 3, 7, 4, 4, 4, 8, 5, 7, 9, 8, 7, 1, 3, 1, 0, 7, 8, 4,
6, 9, 5, 2, 8, 5, 2, 7, 3, 8, 4, 4, 6, 3, 5, 9, 2, 8, 9, 8, 7,
1, 6, 5, 1, 4, 4, 1, 5, 8, 7, 5, 9, 0, 7, 4, 6, 5, 3, 6, 1, 2,
9, 6, 2, 1, 1, 8, 4, 1, 2, 6, 6, 0, 0, 4, 9, 0, 8, 9, 5, 7, 7,
2, 3, 8, 4, 2, 7, 8, 7, 5, 3, 4, 4, 6, 9, 5, 0, 4, 8, 7, 1, 6,
3, 1, 9, 7, 4, 9, 0, 4, 0, 3, 5, 8, 0, 8, 6, 7, 8, 1, 0, 2, 0,
8, 3, 0, 1, 1, 7, 6, 6, 2, 2, 8, 1, 7, 8, 2, 5, 2, 5, 8, 4, 0,
0, 2, 4, 2, 8, 3, 4, 2, 5, 6, 4, 4, 8, 8, 7, 2, 3, 8, 0, 0, 6,
4, 2, 1, 6, 7, 1, 5, 3, 7, 1, 2, 3, 4, 5, 1, 8, 1, 5, 1, 3, 1,
8, 5, 1, 0, 1, 1, 8, 4, 6, 2, 6, 8, 0, 2, 7, 4, 3, 0, 8, 5, 0,
1, 2, 8, 1, 2, 9, 0, 4, 8, 5, 5, 8, 1, 5, 8, 9, 5, 2, 9, 8, 2,
2, 0, 2, 6, 1, 9, 0, 5, 8, 4, 6, 9, 1, 6, 8, 0, 7, 0, 3, 5, 5,
9, 5, 9, 9, 6, 1, 9, 2, 8, 2, 7, 6, 8, 0, 8, 7, 1, 4, 2, 2, 7,
6, 1, 7, 0, 9, 7, 6, 4, 4, 3, 3, 5, 7, 7, 8, 9, 6, 9, 6, 3, 7,
6, 3, 2, 5, 2, 5, 8, 2, 7, 1, 0, 7, 7, 5, 6, 8, 9, 2, 3, 4, 9,
6, 1, 3, 9, 1, 9, 0, 5, 6, 7, 0, 7, 6, 0, 5, 3, 7, 4, 5, 0, 2,
1, 1, 8, 2, 4, 8, 4, 5, 4, 8, 2, 2, 6, 1, 7, 0, 9, 3, 1, 5, 4,
0, 4, 2, 9, 4, 5, 4, 7, 7, 0, 2, 1, 7, 5, 3, 5, 6, 0, 7, 3, 6,
5, 9, 5, 4, 4, 1, 6, 5, 6, 1, 1, 4, 2, 1, 9, 7, 4, 6, 3, 6, 9,
1, 3, 4, 0, 1, 8, 1, 5, 0, 3, 4, 9, 3, 1, 7, 8, 2, 2, 2, 2, 5,
1, 4, 0, 2, 2, 2, 1, 2, 9, 9, 8, 2, 9, 6, 0, 4, 9, 5, 2, 1, 3,
7, 0, 2, 5, 8, 5, 0, 2, 7, 0, 2, 6, 2, 4, 7, 6, 1, 2, 3, 5, 7,
5, 6, 2, 1, 5, 0, 2, 1, 2, 3, 4, 7, 8, 3, 8, 0, 8, 2, 5, 5, 8,
0, 1, 3, 3, 7, 5, 9, 8, 8, 1, 5, 0, 5, 4, 1, 9, 2, 1, 0, 9, 1,
0, 6, 7, 8, 4, 9, 7, 9, 0, 0, 8, 2, 5, 1, 7, 0, 7, 5, 8, 5, 9,
6, 6, 6, 3, 1, 5, 0, 8, 3, 0, 3, 4, 8, 4, 3, 3, 9, 3, 0, 7, 8,
9, 3, 4, 5, 6, 0, 9, 7, 2, 1, 1, 8, 4, 6, 0, 3, 4, 7, 4, 6, 7,
9, 3, 0, 3, 9, 6, 9, 2, 2, 2, 5, 5, 9, 0, 0, 6, 2, 4, 1, 1, 7,
6, 3, 9, 5, 6, 6, 6, 8, 8, 1, 2, 0, 4, 3, 0, 9, 4, 5, 4, 9, 1,
7, 7, 2, 1, 1, 0, 0, 0, 9, 3, 3, 1, 9, 3, 3, 7, 3, 7, 1, 2, 2,
6, 0, 4, 8, 9, 0, 7, 8, 3, 8, 3, 4, 1, 2, 8, 1, 6, 0, 1, 2, 1,
9, 2, 8, 3, 2, 5, 8, 5, 9, 3, 2, 1, 6, 9, 7, 6, 5, 3, 0, 1, 4,
4, 2, 8, 4, 4, 2, 0, 9, 0, 7, 7, 7, 6, 4, 0, 6, 9, 2, 4, 7, 2,
3, 9, 9, 8, 3, 8, 3, 8, 1, 3, 6, 9, 8, 5, 8, 1, 4, 2, 0, 2, 9,
4, 2, 7, 6, 1, 9, 6, 3, 0, 4, 1, 8, 1, 3, 4, 5, 2, 0, 5, 5, 3,
8, 0, 9, 0, 1, 3, 4, 8, 1, 5, 0, 9, 6, 5, 0, 7, 2, 8, 2, 3, 2,
9, 9, 2, 4, 7, 0, 8, 6, 4, 0, 8, 6, 8, 3, 6, 6, 7, 5, 3, 0, 1,
3, 7, 1, 6, 3, 8, 4, 5, 4, 1, 2, 9, 0, 5, 7, 1, 7, 1, 2, 9, 3,
8, 1, 2, 7, 5, 3, 8, 7, 1, 7, 3, 0, 8, 2, 9, 6, 8, 6, 0, 9, 9,
5, 4, 3, 8, 1, 2, 2, 2, 2, 3, 9, 8, 5, 5, 5, 5, 2, 9, 8, 8, 1,
3, 0, 1, 1, 9, 3, 7, 7, 7, 2, 2, 3, 6, 3, 7 };
Map<Integer, Integer> map = new HashMap<Integer, Integer>();
List<Integer> list = new ArrayList<Integer>();
for (int n : nums)
// key - value (数据 - 数据出现的次数)
map.put(n, map.get(n) == null ? 1 : map.get(n) + 1);
for (int n : map.keySet()) { // 将数据出现的次数存放到ArrayList数列中