C++ :

#include <iostream>
using namespace std;
int n,ans=0;
char a[10];
int ch()
{
	int b[10]={0};
	int i,sum=0;
	for(i=0;i<n;i++)
	b[i]=i+1;
	for(i=0;i<n-1;i++)
	{
		if(a[i-1]==' '&&i!=0&&a[i]==' ')
		return 0;
		if(a[i]==' ')
		{
			b[i]=b[i]*10+b[i+1];
			b[i+1]=0; 
		 } 
	}
	
	sum=b[0];
	 for(i=0;i<n-1;i++)
	 {
	 	if(a[i]=='-')
		 {
		 	sum=sum-b[i+1];
		  } 
		  else
		  sum=sum+b[i+1];
	 }
	if(sum==0)
	return 1;
	return 0;	
}
void dfs(int s)
{
	int i;
	if(s==n)
	{
		if(ch())
		{
			ans++;
			if(ans%3==1)
			{
		
			for(i=0;i<n-1;i++)
			{
				cout<<i+1<<a[i];
			}
			cout<<n<<endl; 	}
		 } 
	}
	else
	{
		a[s]=' ';
		dfs(s+1);
		a[s]='+';
		dfs(s+1);
		a[s]='-';
		dfs(s+1);
		
	}
}
int main()
{
	cin>>n;
	 dfs(0);
 } 

Pascal :

var n:integer;
procedure work;
  var c:array[0..8] of integer;
      s:array[1..9] of longint;
      k,i,p,t:integer;
      sum:longint;
  begin
    fillchar(c,sizeof(c),0);
    while c[0]=0 do
      begin
        fillchar(s,sizeof(s),0);
        k:=1;
        for i:=1 to n-1 do
          begin
            s[k]:=s[k]*10+i;
            if c[i]<>0 then k:=k+1;
          end;
        s[k]:=s[k]*10+n;
        sum:=s[1];
        p:=2;
        for i:=1 to n-1 do
          if c[i]<>0 then
            begin
              if c[i]=1 then sum:=sum+s[p] else sum:=sum-s[p];
              p:=p+1;
            end;
        if sum=0 then
          begin
            for i:=1 to n-1 do
              begin
                write(i);
                if c[i]=0 then write(' ');
                if c[i]=1 then write('+');
                if c[i]=2 then write('-');
              end;
            writeln(n);
          end;
        t:=n-1;
        while c[t]=2 do
          begin
            c[t]:=0;
            t:=t-1;
          end;
        c[t]:=c[t]+1;
      end;
  end;
 begin
  readln(n);
  work;
end.

Java :

import java.util.Scanner;

public class Main {
	public static int n;
	public static int shulie[];
	public static char fuhao[];
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner in=new Scanner(System.in);
		n=in.nextInt();
		shulie=new int[n];
		fuhao=new char[n-1];
		for(int i=0;i<n;i++){
			shulie[i]=i+1;
		}
		
		dfs(0);
	}
	
	public static void dfs(int k){
		if(k==n-1){
			for(int i=0;i<n-1;i++){
				if(fuhao[i]==' '){
					for(int j=i;j>=0;j--){
						if(shulie[j]!=0){
							shulie[j]=shulie[j]*10+shulie[i+1];
							shulie[i+1]=0;
							break;
						}
					}
					
				}
			}
			for(int i=0;i<n-1;i++){
				if(fuhao[i]=='+'){
					shulie[i+1]=shulie[i]+shulie[i+1];
				}
				else if(fuhao[i]=='-'){
					shulie[i+1]=shulie[i]-shulie[i+1];
				}
				else if(fuhao[i]==' '){
					shulie[i+1]=shulie[i];
				}
			}
			if(shulie[n-1]==0){
				for(int i=0;i<n;i++){
					shulie[i]=i+1;
				}
				for(int i=0;i<n-1;i++){
					System.out.print(shulie[i]+""+fuhao[i]);
				}
				System.out.println(shulie[n-1]);
			}
			else{
				for(int i=0;i<n;i++){
					shulie[i]=i+1;
				}
			}
			return;
		}
		
		fuhao[k]=' ';
		dfs(k+1);
		fuhao[k]='+';
		dfs(k+1);		
		fuhao[k]='-';
		dfs(k+1);
			
		
	}

}