C and C++ Program to Check Whether a Given Year is Leap Year or Not

This is post contains a C program and a C++ program to check whether an input year is leap year or not. A year is a leap year if:

1. The year is divisible by 400
2. The year is divisible by 4 but not divisible by 100.

Any other year is not a leap year.

C program

#include <stdio.h>
void main()
{
int year;
printf("Enter a year to check if it is a leap year\n");
scanf("%d", &year);
if(year%400==0 || ((year%4=0) && (year%100!=0)))
printf("%d is a leap year.\n", year); else
printf("%d is not a leap year.\n", year);
}

C++ program

#include <iostream.h>
void main()
{
int year;
cout<<"Enter a year to check if it is a leap year or not";
cin>>year;
if(year%400==0 || ((year%4=0) && (year%100!=0)))
cout<<"\n"<<year<<"is a leap year."; else
cout<<"\n"<<year<<"is NOT a leap year."; 
}

C and C++ Programs to Check Whether a Given Number is Armstrong Number or Not

This post contains two programs, a C++ program and a C program. These are programs to check whether a given number is an Armstrong number or not. An Armstrong number is a positive integer for which the sum of 'n'th power of all of its digits is equal to the number itself. For example, 153 is a 3 digit Armstrong number because 1³+5³+3³=153.

C ++ program:

# include <iostream.h>

# include <conio.h>

# include <math.h>

void main ()

{

clrscr();

int a,b=0,sum=0;

long int n;

cout<<"Enter the number to be checked\n ";

cin>>n;

if(n<1)
{
cout<<"\nThe number should be greater than 0";
}
else
{
a=n;
//counting the digits
while (a>0) 
{
a=a/10; 
b++;
}
a=n;
//adding up bth power of digits
while(a>0)
{
sum=sum+pow(( a%10) ,b);
a=a/10;
}
if(sum==n)
cout<<"\nThe number is an ARMSTRONG number";
else
cout<<"\nThe number is NOT an ARMSTRONG number";
}
getch();
}

C Program:

# include <stdio.h>

# include <conio.h>

# include <math.h>

void main ()

{

clrscr();

int a,b=0,sum=0;

long int n;

printf("Enter the number to check\n ");

scanf("%i",&n);
if(n<1)
{
printf ("\nThe number should be greater than 0");
}
else
{
a=n;
//counting the digits
while (a>0) 
{
a=a/10; 
b++;
}
a=n;
//adding up bth power of digits
while(a>0)
{
sum=sum+pow(( a%10) ,b);
a=a/10;
}
if(sum==n)
printf ("\nThe number is an ARMSTRONG number");
else
printf ("\nThe number is NOT an ARMSTRONG number");
}
getch();
} 

C Program to Sort a Matrix Column wise using Pointers

This is a c program to sort a mxn matrix column wise in ascending order using pointers. To sort column wise in descending order, just replace the '>' symbol in the comparing line of code into '<'. That part of the code is marked with a comment 'comparison'.

#include<stdio.h>

main()

{

int a[7][7],i,j,k,m,n,temp;

//reading
printf("enter number of rows of matrix\n");
scanf("%i",&m);
printf("enter number of columns of matrix\n");
scanf("%i",&n);
printf("enter the elements\n");
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
scanf("%d",&a[i][j]);
}
//displaying
printf("the matrix you entered:\n");
for(i=0;i<m;i++)
{
printf("\n");
for(j=0;j<n;j++)
{
printf("%4d",*(*(a+i)+j));
}
}