HDOJ-- 1303 Doubles

Doubles

[b]Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)

Total Submission(s): 5216    Accepted Submission(s): 3538[/b]

[align=left]Problem Description[/align]
As part of an arithmetic competency program, your students will be given randomly generated lists of from 2 to 15 unique positive integers and asked to determine how many items in each list are twice some other item in the same list.
You will need a program to help you with the grading. This program should be able to scan the lists and output the correct answer for each one. For example, given the list

1 4 3 2 9 7 18 22

your program should answer 3, as 2 is twice 1, 4 is twice 2, and 18 is twice 9.

 

[align=left]Input[/align]
The input file will consist of one or more lists of numbers. There will be one list of numbers per line. Each list will contain from 2 to 15 unique positive integers. No integer will be larger than 99. Each line will be terminated
with the integer 0, which is not considered part of the list. A line with the single number -1 will mark the end of the file. The example input below shows 3 separate lists. Some lists may not contain any doubles.

[align=left]Output[/align]
The output will consist of one line per input list, containing a count of the items that are double some other item.

 

[align=left]Sample Input[/align]

1 4 3 2 9 7 18 22 0
2 4 8 10 0
7 5 11 13 1 3 0
-1

 

[align=left]Sample Output[/align]

3
2
0

import java.util.Scanner;

public class Main{
//有多少对数的倍数为2
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
while(sc.hasNext()){
String str=sc.nextLine();
String[] strs=str.split(" ");
int[] arr=new int[strs.length];
for(int i=0;i<arr.length;i++){
arr[i]=Integer.parseInt(strs[i]);
}
if(arr[0]==-1){
return;
}
int t=0;
for(int i=0;i<arr.length;i++){
for(int j=0;j<arr.length;j++){
if(i!=j){      //不是同一个数
if(arr[j]!=0){  //除数不能为0
double two=(arr[i]*1.0)/(1.0*arr[j]);
if(two==2){
t++;
break;
}
}
}
}
}
System.out.println(t);
}
}
}