Euler Problem 42 solution

Time (s): ~0.067

package margusmartseppcode.From_40_to_49;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.HashMap;
import java.util.Scanner;
import java.util.Map;

public class Problem_42 {
 static int sumStringChars(String s) {
  if (s == null)
   return 0;
  int n = s.length(), sum = 0;
  for (int i = 0; i < n; i++)
   sum += s.charAt(i) - '@';
  return sum;
 }

 public static void main(String[] args) throws FileNotFoundException {
  Map<Integer, Integer> map = new HashMap<Integer, Integer>();
  String raw = new Scanner(new File("words.txt")).next();
  String str[] = raw.substring(1, raw.length() - 1).split("\",\"");
  int count = 0;

  for (String s : str) {
   int tmp = sumStringChars(s);
   map.put(tmp, map.containsKey(tmp) ? map.get(tmp) + 1 : 1);
  }

  for (Integer i : map.keySet())
   if ((((Math.sqrt(1 + 8 * i) - 1) / 2) % 1 == 0))
    count += map.get(i);

  System.out.println(count);
 }
}