C++ :

#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
	int p[9]={1,2,3,4,5,6,7,8,9};
	int cnt=0;
	do
	{
		if((p[0]*100+p[1]*10+p[2]+p[3]*100+p[4]*10+p[5])==(p[6]*100+p[7]*10+p[8]))
			cnt++;	
	}while(next_permutation(p,p+9));
	cout<<cnt;
	return 0;
}

Pascal :

begin
  write(336);
end.

Java :

public class Main {
public static void main(String []args){
	String test;
	int count = 0;
	//System.out.println(f("456789123"));
	for(int i=300;i<1800;i++){
		for(int j=100;j<1000&&j<i;j++){
			int t = i-j;
			test=i+""+""+j+""+t+"";
			//System.out.println(test);
			if(test.length()==9 &&f(test)){
				//System.out.println(test);
				count++;
			}
			test = "";
		}
	}
	System.out.println(count);
}
public static boolean f(String s){
	char a[]={'1','2','3','4','5','6','7','8','9'};
	for(int i=0;i<s.length();i++){
		for(int j=0;j<a.length;j++){
			if(a[j]=='o') continue;
			if(s.charAt(i)==a[j]) a[j]='o';
		}
	}
	for(int i=0;i<a.length;i++){
		if(a[i]!='o') return false;
	}
	return true;
}
}