First Day C++ program

 First Day C++ program

1. Hello World program

Code:

#include<iostream>

using namespace std;

main()

{

cout<<"Hello World";

return 0;

}

2. Program for simple interest

Code:

 #include<iostream>

using namespace std;

main()

{

int p,r,t;

float si;

cout<<"type principle rate and time"<<endl;

cin>>p>>r>>t;

si=(p*r*t)/100.0;  // 100.0 because of type casting

cout<<si;

return 0;

}

3. Program to find sum of numbers from 1 to N

Code:

#include<iostream>

using namespace std;

main()

{

int n;

cin>>n;

int i=1;

int sum=0;

while(i<=n){

sum=sum+i;

i=i+1;

}

cout<<"Sum of 1 to "<<n<<" is : "<<sum<<endl;

return 0;

}

4. Program to find sum of Digits

Code:

#include<iostream>

using namespace std;

main()

{

int n;

cin>>n;

int sum=0;

while(n>0){

int last_digit=n%10;

sum=sum+last_digit;

n=n/10; // update statement 

}

cout<<sum<<endl;

return 0;

}