c++ program that display following triangle pattern.

for n=3;

pattern:      

        1
       -2  3
       -4  5  -6


 
#include <iostream>
using namespace std;

int main()
{
int i,j,k,x,n;
//input from user
cout<<"Enter a number ";
cin>>k;
x=1;
for(i=1;i<=k;i++)
{



for(n=0;n<k-i;n++)
{
cout<<" ";
}
for(j=1;j<=i;j++)
{
if(x%2==0)
{
cout<<-x<<" ";
}
else
{

cout<<x<<" ";
}
x=x+1;
}
cout<<"\n";
}
return 0;
}