package com.meituan.online;  import java.util.*;  /**  * Created by bruceguo on 2017/9/14.  */ public class Problem1 { private static Set<Long> resultSets = new HashSet<>();   public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);  int n = scanner.nextInt();  int[] nums = new int[n];  for (int i = 0; i < n; i++) {
            nums[i] = scanner.nextInt();  } int sum = 0;  for (int i = 0; i < nums.length; i++) { for (int j = i + 1; j < nums.length; j++) { process(nums[i], nums[j]);  }
        }
        System.out.println(resultSets.size());  } private static void process(int n1, int n2) { long result = 0;  //n1前，n2后  result = n2 + n1 * (int) Math.pow(10, (String.valueOf(n2).length()));  if (result % 7 == 0) { resultSets.add(result);  } //n1后，n2前  result = n1 + n2 * (int) Math.pow(10, (String.valueOf(n1).length()));  if (result % 7 == 0) { resultSets.add(result);  }
    }
}

就想问为什么AC总是10%！！！输入没有用while循环的原因？？？