Below is the syntax highlighted version of Goldbach.java from §1.4 Arrays.

/******************************************************************************
 * Compilation: javac Goldbach.java
 * Execution: java -Xmx900MB -Xms900MB Goldbach n
 *
 * Computes all primes less than n and tries to express n as a sum
 * of two primes. Goldbach's conjecture says that this is always
 * possible if n is even and greater than 2. When n is odd, these
 * are called prime pairs.
 *
 * Sample execution:
 *
 * % java Goldbach 10003292
 * 10003292 =わ 349 +たす 10002943
 *
 * % java Goldbach 10000001
 * 10000001 is not expressible as the sum of two primes
 *
 * % java Goldbach 10000021
 * 10000021 =わ 2 +たす 10000019
 *
 ******************************************************************************/
publicclassGoldbach{
publicstaticvoidmain(String[] args){
int n = Integer.parseInt(args[0]);
boolean[] isPrime =newboolean[n];
for(int i =2; i < n; i++)
 isPrime[i]=true;
// determine primes < n using Sieve of Eratosthenes
for(int factor =2; factor*factor < n; factor++){
if(isPrime[factor]){
for(int j = factor; factor*j < n; j++)
 isPrime[factor*j]=false;
}
}
// count primes
int primes =0;
for(int i =2; i < n; i++)
if(isPrime[i]) primes++;
 System.out.println("Done tabulating primes.");
// store primes in list
int[] list =newint[primes];
int count =0;
for(int i =0; i < n; i++)
if(isPrime[i]) list[count++]= i;
// check if n can be expressed as sum of two primes
int left =0, right = count-1;
while(left <= right){
if(list[left]+ list[right]== n)break;
elseif(list[left]+ list[right]< n) left++;
else right--;
}
if(list[left]+ list[right]== n)
 System.out.println(n +" = "+ list[left]+" + "+ list[right]);
else
 System.out.println(n +" not expressible as sum of two primes");
}
}