Nested Loops in C

Program 1

// Program for Pyramid Structure
#include<stdio.h>
#include<conio.h>
int main()
{
      system("cls");
      int n,i,j;
      printf("Enter the limit");
      scanf("%d",&n);
      for(i=1;i<=n;i++)
      {
             for(j=1;j<=i;j++)
             {
                printf("*");
             }
             printf("\n");
      }
     return 0;         
}

Program 2

#include<stdio.h>
#include<conio.h>
int main()
{
      system("cls");
      int n,i,j;
      printf("Enter the limit");
      scanf("%d",&n);
      for(i=1;i<=n;i++)
      {
             for(j=1;j<=i;j++)
             {
                printf( " %d ",j);
             }
             printf("\n");
      }
     return 0;         
}

Program 3

#include<stdio.h>
#include<conio.h>
int main()
{
      system("cls");
      int n,i,j;
      printf("Enter the limit");
      scanf("%d",&n);  // n=5
      for(i=n;i>=1;i--)
      {
          for(j=1;j<=i;j++)
          {
              //printf("*");
                printf(" %d ",j);
          }
          printf("\n");
      }
     return 0;         
}

Program 4

#include<stdio.h>
#include<conio.h>
int main()
{
      system("cls");
      int n,i,j;
      printf("Enter the limit");
      scanf("%d",&n);  // n=5
      for(i=1;i<=n;i++)
      {
          for(j=n;j>=i;j--)
          {
              //printf("*");
                printf(" %d ",j);
          }
          printf("\n");
      }
     return 0;         
}