Output as tringle:: increase +1

#include<conio.h>

#include<stdio.h>

  void main()

  {   clrscr();

      int i,n,m,a,j;

      a=1;

      scanf("%d",&n);

      for(i=1;i<=n;i++)

      {     for(j=1;j<=i;j++)

                   {      printf("%d ",a);

                                  a++;                     }

                                  printf("\n");

                                  }

                                  getch();

                                  }