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@imduffy15
Created August 14, 2012 17:51
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/**
* Read in N integers and counts the number of triples
* that sum to exactly 0
*
* @author Ian Duffy
* @version 0.0.1
*
*/
import java.util.*;
import java.io.*;
class Threesum {
public static int count(int[] a) {
int cnt=0;
for(int i=0;i<a.length;i++) {
for(int j=i+1;j<a.length;j++) {
for(int k=j+1;k<a.length;k++) {
if(a[i] + a[j] + a[k] == 0) {
cnt++;
}
}
}
}
return cnt;
}
public static void main(String[] args) {
try {
Scanner f = new Scanner(new File(args[0]));
if(f.hasNextLine()) {
String[] fields = f.useDelimiter("\\A").next().trim().split("\\s+");
int[] vals = new int[fields.length];
for(int i=0;i<fields.length;i++) {
vals[i] = Integer.parseInt(fields[i]);
}
System.out.println(count(vals));
}
} catch(IOException e) {
System.out.println(e.getMessage());
}
}
}
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