Two integers are called "friend numbers" if they share the same sum of their digits, and the sum is their "friend ID". For example, 123 and 51 are friend numbers since 1+2+3 = 5+1 = 6, and 6 is their friend ID. Given some numbers, you are supposed to count the number of different friend ID's among them.
Input Specification:
Each input file contains one test case. For each case, the first line gives a positive integer N. Then N positive integers are given in the next line, separated by spaces. All the numbers are less than 104.
Output Specification:
For each case, print in the first line the number of different friend ID's among the given integers. Then in the second line, output the friend ID's in increasing order. The numbers must be separated by exactly one space and there must be no extra space at the end of the line.
Sample Input:
8
123 899 51 998 27 33 36 12
Sample Input:
4
3 6 9 26
解题思路：
题目大意：求一串数字每个数的各位数字之和（无重复）。
可以用哈希表存储，既可以用set直接存储，也可以用数组模拟哈希表。
java代码：import java.io.*;
import java.util.*;
public class Main {
public static void main(String[] args) throws NumberFormatException, IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
br.readLine();
String[] split = br.readLine().split(" ");
List list = new ArrayList();
for(int i = 0; i < split.length;i++) {
list.add(split[i]);
}
Set set = new HashSet();
List ans = new ArrayList();
for(int i = 0; i < list.size();i++) {
String temp = list.get(i);
int sum = 0;
for(int j = 0; j < temp.length();j++) {
sum += Integer.parseInt(temp.charAt(j) + "");
}
if(set.contains(sum)) {
continue;
}else {
set.add(sum);
ans.add(sum);
}
}
Collections.sort(ans);
StringBuilder builder = new StringBuilder();
builder.append(ans.size() + "n");
for(int i = 0; i < ans.size();i++) {
builder.append(ans.get(i) + " ");
}
System.out.print(builder.toString().trim());
}
}
PTA提交截图：
