题解 | #数组中重复的数字#

import java.util.*;

public class Solution {

public int duplicate (int[] numbers) {
    
    if(numbers == null){
        return -1;
    }
    
    for(int i=0;i<numbers.length-1;i++){
        for(int j=i+1;j<numbers.length;j++){
            if(numbers[i]==numbers[j]){
                return numbers[i];
            }
        }
    }
    
    return -1;
}

}