11683 - Laser Sculpture - JAVA

package org.goro.uva.m;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class LaserSculpture {

 public static void main(String[] args) throws IOException {

  Reader.init(System.in);
  StringBuilder sb = new StringBuilder();

  int height = Reader.nextInt();
  while (height > 0) {
   int lenght = Reader.nextInt();

   int lasers = cut(height, lenght);
   sb.append(lasers);
   
   height = Reader.nextInt();
   if (height > 0) {
    sb.append("\n");
   }
  }
  System.out.println(sb);
 }

 private static int cut(int maxHeight, int lenght) throws IOException {
  int cut = 0;

  int last = maxHeight;
  
  for (int j = 0; j < lenght; j++) {
   int curr = Reader.nextInt();

   if (curr < last) {
    cut += last - curr;
   }

   last = curr;
  }
  return cut;
 }

}

/** Class for buffered reading int and double values */
/** http://www.cpe.ku.ac.th/~jim/java-io.html */
class Reader {
 static BufferedReader reader;
 static StringTokenizer tokenizer;

 /** call this method to initialize reader for InputStream */
 static void init(InputStream input) {
  reader = new BufferedReader(new InputStreamReader(input));
  tokenizer = new StringTokenizer("");
 }

 /** get next word */
 static String next() throws IOException {
  while (!tokenizer.hasMoreTokens()) {
   tokenizer = new StringTokenizer(reader.readLine());
  }
  return tokenizer.nextToken();
 }

 static int nextInt() throws IOException {
  return Integer.parseInt(next());
 }

 static double nextDouble() throws IOException {
  return Double.parseDouble(next());
 }
}