Basic of C program:- comment and print function.

                
// This is a single line comment...
            
/*this is a multi line
comment*/
            
#include<stdio.h>   //Header file..
#include<conio.h>  //Header file..
int main()        //first Code runs from here..
{
    printf("Hello world!");  //Printf is the function to print..
    return 0;       //Returns the value. Here, it return nothings means 0..
}  
                
                

C program to find Simple Intrest.

                
#include<stdio.h>
#include<conio.h>

int main()
{
    float si, p, t, r;
    printf("Enter principle(P): \n");
    scanf("%f",&p);
    printf("Enter time(T): \n");
    scanf("%f",&t);
    printf("Enter rate(R): \n");
    scanf("%f",&r);
    si=(p*t*r)/100; //formula to calculate Simple intrest......
    printf("The simple intrest is: %f", si);
    return 0;
}
                
                

C program to find whether the entered number is positive or negative.

                
#include<stdio.h>
#include<conio.h>
int main()
{
    int a;
    printf("\nEnter a number(Not zero): ");
    scanf("%d",&a);

    if (a < 0)
    {
        printf("\nIts negative number");
    }
    else
    {
        printf("\nIts positive number");
    }


        return 0;
}
                
                

C program to find whether the entered number is odd or even.

                
#include<stdio.h>
#include<conio.h>
int main()
{
    int a;
    printf("\nEnter a number: ");
    scanf("%d",&a);

    if (a%2==0)
    {
        printf("\nIts even number");
    }
    else
    {
        printf("\nIts odd number");
    }


    return 0;
}
                
                

C program to arrange 10 user input number in ascending order.

#include<stdio.h>
#include<conio.h>
int main()
{
int n[50],t;
    for (int i = 0; i < 10; i++)
    {
        printf("\nEnter a number: ");
        scanf("%d",&n[i]);
    }

    for (int i = 0; i < 10-1; i++)
    {
        for (int j = i+1; j < 10; j++)
        {
            if (n[i]>n[j])
            {
                t=n[i];
                n[i]=n[j];
                n[j]=t;

            }
            
        }
        
    }
    printf("\nNumber in ascending order are: ");
    for (int i = 0; i < 10; i++)
    {
        printf("\n%d",n[i]);
    }
    
    
    
    return 0;
}

C program to show simple switch case.

#include<stdio.h>
#include<conio.h>
int main()
{
    int a,b,ch,m;
    printf("\nEnter first number: ");
    scanf("%d",&a);
    printf("\nEnter second number: ");
    scanf("%d",&b);
    printf("\nEnter 1 for finding sum\nEnter 2 for finding differnce\nEnter 3 for finding greaternumber\nyou have entered: ");
    scanf("%d",&ch);
    switch (ch)  //switch to the var ch
    {
    case 1:
        m=a+b;
        printf("\nThe sum is: %d",m);
        break;
    case 2:
        m=a-b;
        printf("\nThe differnce is: %d",m);
        break;
    case 3:
       if (a>b) // to find greates number
       {
           printf("%d is greates number\n",a);  
       }
       else
       {
           printf("%d is greates number\n",b);
       }
    
        break;

    default:
    printf("\nYou should press 1/2/3 only\nThank you");
        break;
    }
    
    return 0;
}

C program to show simple array example And to find Smallest number in array.

#include<stdio.h>
#include<conio.h>
int main()
{
int max,i;
int a[10]; //array declearing......
printf("\nEnter 5 positive numbers:\n");
for (int i = 0; i < 5; i++) //array always starts from 0..
{
    scanf("%d",&a[i]);
}
    max=a[0];
    for (int i = 0; i > 5; i++)
    {
        if (a[i]<max)
        {
          max=a[i];
        }
        
    }
    printf("\nSmallest number in array is: %d",max);
    
    return 0;
}

C program to display number of digit you entered.

#include<stdio.h>
#include<conio.h>
int main()
{
    int n,count=0;
    printf("Enter the number: ");
    scanf("%d",&n);
    for ( n == 0; n++;)
    {
        count=count+1;
        n=n/10;
    }
    printf("\nThere are %d digit in your number",count);
    

    return 0;
}
    

C program to calculate electricity bill.

#include<stdio.h>
#include<conio.h>
int main()
{
    float n,u;
    printf("Enter Unit:");
    scanf("%f",&n);
    if (n<=20)
    {
        printf("\nTotal amount(Rs.) = 80");
    }
    else if (n<=30)
    {
        u=n*7.5+80;
        printf("\nTotal amount(Rs.) = %f",u);
    }
    else if (n<=50)
    {
        u=n*10+80;
        printf("\nTotal amount(Rs.) = %f",u);
    }
    else if (n<=80)
    {
        u=n*12.5+80;
        printf("\nTotal amount(Rs.) = %f",u);
    }
    else
    {
        u=n*15+80;
        printf("\nTotal amount(Rs.) = %d",u);
    }
    
    
    return 0;
}
    

C program to display fibonacci series to n term.

#include<stdio.h>
#include<conio.h>
int main()
{
    int a=1,b=1,c=0,n;
    printf("\nEnter the limit: ");
    scanf("%d",&n);
    for (int i = 1; i <= 10; i++)
    {
        printf("%d, ",a);
        c= a+b;
        a=b;
        b=c;
    }
    

    return 0;
}
    

C program to find whether the entered number is Perfect number or not.

#include<stdio.h>
#include<conio.h>
int main()
{
    int n,sum=0;
    printf("Enter the number: ");
    scanf("%d",&n);
    for (int i = 1; i < n; i++)
    {
        if (n%i==0)
        {
            sum=sum+i;
        }
    }
    if (sum==n)
    {
        printf("\nPerfect number");
    }
    else
    {
        printf("\nNot perfect");
    }
    
    
    return 0;
}