triangles of numbers v1.c

/*
triangles v1 .c

C program to print triangles of numbers

Enter number of lines: 5

*/

#include<stdio.h>

int main(void)
{
  int r,n,s,k,rows=5,memRows;

// enter 5 number of rows, rows=5
  printf("\n Enter number of rows: ");
  scanf("%d",&rows);


    printf("\n 1. \n\n");
/*

    1
   1 2
  1 2 3
 1 2 3 4
1 2 3 4 5

*/

    memRows = rows;                     // we remember rows in memRows

    for (r=1; r<=rows; r++)             // Loop to print rows
    {
        for (s=1; s<memRows; s++)       // Loop to print spaces in a row
          printf(" ");

        memRows--;                      // decrease membered rows

        for (n=1; n<=rows-memRows; n++) // Loop to print numbers in a row
          printf("%d ",n);

        printf("\n");
    }


    printf("\n 2. \n\n");

/*

    1
   12
  123
 1234
12345

*/

    memRows = rows;                     // we remember rows in memRows

    for (r=1; r<=rows; r++)             // Loop to print rows
    {
        for (s=1; s<memRows; s++)       // Loop to print spaces in a row
          printf(" ");

        memRows--;                      // decrease membered rows

        for (n=1; n<=rows-memRows; n++) // Loop to print numbers in a row
          printf("%d",n);

        printf("\n");
    }


    printf("\n 3. \n\n");

/*

    1
   121
  12321
 1234321
123454321

*/

    for(r=1; r<=rows; r++)              // Loop to print rows
    {
        for(s=1; s<=rows-r; s++)        // Loop to print spaces in a row
            printf(" ");

        for(s=1,k=2*r-1; s<=2*r-1; s++,k--) // Loop to print numbers in a row
        {
            if (s <= k)
                printf("%d", s);
            else
                printf("%d", k);
        }

        printf("\n");
    }


    printf("\n 4. \n\n");

/*

1
1 2
1 2 3
1 2 3 4
1 2 3 4 5

*/

    for(r=1; r<=rows; r++)
    {
        for(n=1; n<=r; n++)
        {
            printf("%d ",n);
        }
        printf("\n");
    }


    printf("\n 5. \n\n");

/*

1 2 3 4 5
1 2 3 4
1 2 3
1 2
1

*/

    for(r=rows; r>=1; r--)
    {
        for(n=1; n<=r; n++)
        {
            printf("%d ",n);
        }
        printf("\n");
    }


  return 0;
}