Program to enter three integers and output the smallest integer using IF.

#include <iostream.h>
#include <conio.h>
int main()
{
clrscr();
int x,y,z,smallest;
cout << "Enter 3 integers : ";
cin>>x>>y>>z;
smallest=x;
if(y<smallest)
smallest=y;
if(z<smallest)
smallest=z;
cout << "The smallest integer out of the 3 integers you typed ";
cout << x << ", " << y << " & " << z << " is : " << "\n" << smallest << "\n";
getch();
return 0;
}

This program takes in three integers x, y and z as a screen input from the user.
It then determines the smallest integer of the three and prints it out using the 'cout' command.

Program to find the sum of either of the diagonals of a 4 x 4 matrix.

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
int x;
int A[4][4],sum=0; //Reading the matrix.
cout << "Enter the elements of the matrix : " << endl;
for(int y=0;y<4;y++)
for (int x=0;x<4;x++)
{
cout << "Element " << x+1 << ", " << y+1 << " : ";
cin>>A[x][y];
}
//Sum of either of the diagonal elements.
for(x=0;x<4;x++)
for(y=0;y<4;y++)
if(x==y)
sum+=A[x][y];
else if(y==4-(1+1));
sum+=A[x][y];
cout << "Sum of either of the diagonal elements is : " << sum;
getch();
}

This program takes in the elements A[x][y] of the 4 x 4 matrix as a screen input from the user.
It then calculates the sum of either of its diagonals and outputs it using the 'cout' command.

Program to enter 10 integers in a single-dimension array and then print out the array in ascending order.

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
int array[10],t;
for(int x=0;x<10;x++)
{
cout << "Enter Integer No. " << x+1 << " : " << endl;
cin>>array[x];
}
for (x=0;x<10;x++)
{
for(int y=0;y<9;y++)
{
if(array[y]>array[y+1])
{
t=array[y];
array[y]=array[y+1];
array[y+1]=t;
}
}
}
cout << "Array in ascending order is : ";
for (x=0;x<10;x++)
cout << endl << array[x];
getch();
}

This program takes in the ten integers array[x] to be stored in the single-dimensional array as a screen input from the user.
It then sorts out these ten integers into ascending order and prints them out using the 'cout' command.

Program to enter a sentence and output the number of uppercase & lowercase consonants, uppercase & lowercase vowels in sentence..

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
char line[80];
int number_of_vowels,uc,lc,uv,lv;
uc=lc=uv=lv=0;
cout << "Enter your sentence : " << endl;
cin.getline(line,80);
for(int x=0; line[x]!='\0';x++)
{
if(line[x]=='A'||line[x]=='E'||line[x]=='I'||line[x]=='O'||line[x]=='U')
uv++;
else if(line[x]=='a'||line[x]=='e'||line[x]=='i'||line[x]=='o'||line[x]=='u')
lv++;
else if(line[x]>+65&&line[x]<=90)
uc++;
else if (line[x]>=97&&line[x]<=122)
lc++;
}
//Printing the output.
cout << "Uppercase Consonants = " << uc << "." << endl;
cout << "Lowercase Consonants = " << lc << "." << endl;
cout << "Uppercase Vowels = " << uv << "." << endl;
cout << "Lowercase Vowels = " << lv << "." << endl;
number_of_vowels=uv+lv;
cout << "Number of vowels = " << number_of_vowels << endl;
getch();
}

This program takes in a sentence as a screen input from the user.
It then computes the number of uppercase and lowercase consonants, uppercase and lowercase vowels and the total number of vowels.
It then outputs it using the 'cout' command.

Program to convert temperatures from Celsius to Fahrenheit and vice versa.

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
int choice;
float ctemp,ftemp;
cout << "1.Celsius to Fahrenheit" << endl;
cout << "2.Fahrenheit to Celsius" << endl;
cout << "Choose between 1 & 2 : " << endl;
cin>>choice;
if (choice==1)
{
cout << "Enter the temperature in Celsius : " << endl;
cin>>ctemp;
ftemp=(1.8*ctemp)+32;
cout << "Temperature in Fahrenheit = " << ftemp << endl;
}
else
{
cout << "Enter the temperature in Fahrenheit : " << endl;
cin>>ftemp;
ctemp=(ftemp-32)/1.8;
cout << "Temperature in Celsius = " << ctemp << endl;
}
getch();
}

This program takes in the user's choice choice as a screen input from the user.
It then asks the user for a temperature in Celsius or Fahrenheit depending on the choice.
It then converts the Celsius temperature to Fahrenheit or vice versa and prints it out using the 'cout' command.

Program to print the first 10 lines of pascal's triangle.

#include <iostream.h>
#include <conio.h>
#include <iomanip.h>
long triangle(int x,int y);
int main()
{
clrscr();
const lines=10;
for (int i=0;i<lines;i++)
for (int j=1;j<lines-i;j++)
cout << setw(2) << " ";
for (int j=0;j<=i;j++)
cout << setw(4) << triangle(i,j);
cout << endl;
getch();
}
long triangle(int x,int y)
{
if(x<0||y<0||y>x)
return 0;
long c=1;
for (int i=1;i<=y;i++,x--)
c=c*x/i;
return c;
}

This program does not take in any screen inputs from the user.
It just prints out the first ten lines of the pascal's triangle using the 'cout' command.

Program to enter a character and output its ASCII code.

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
char charac;
cout << "Enter the character : " << endl;
cin>>charac;
int num1=charac;
cout << "The ASCII code for " << charac << " is " << num1 << "." << endl;
getch();
}

This program takes in any character charac as a screen input from the user.
It then finds out its ASCII code and outputs it using the 'cout' command.

Program to enter a letter and output the next 2 letters

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
char charac;
cout << "Enter your letter : " << endl;
cin>>charac;
cout << "The 2 letters are : " << endl;
cout << (char)(charac-1) << endl;
cout << (char)(charac+1) << endl;
getch();
}

This program takes in a letter charac of the English alphabet as a screen input from the user.
It then determines its previous letter and next letter and prints it out using the 'cout' command.

Program to identify if an input is a symbol, digit or character.

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
char charac;
cout << "Enter your input : " << endl;
cin>>charac;
if(((charac>='A')&&(charac<='Z'))||((charac>='a')&&(charac<='z')))
cout << "Your input " << charac << " is a character." << endl;
else if((charac>='0')&&(charac<='9'))
cout << "Your input " << charac << " is a digit." << endl;
else
cout << "Your input " << charac << " is a symbol." << endl;
getch();
}

This program takes in a character, a digit or a symbol charac as a screen input from the user.
It then identifies whether the input is a symbol, a digit or a character and outputs the appropriate message using the 'cout' command.

Program to compute the fibonacci series.

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
int a,b,x,y,num1,ct;
a=0;
b=1;
cout << "Enter the number of terms (less than 25) : " << endl;
cin>>num1;
cout << a << endl;
cout << b << endl;
for(ct=1;ct<=num1-2;ct++)
{
x=a+b;
cout << x << endl;
y=a;
a=b;
b=x;
}
getch();
}

This program takes in the number of terms num1 in the fibonacci series (less than 25) as a screen input from the user.
It then computes the fibonacci series and prints it out using the 'cout' command.

Program to find the total days in the year till date.

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
int day,month,total;
int days_per_month[12]={31,28,31,30,31,30,31,31,30,31,30,31};
cout << "Enter the month : " << endl;
cin>>month;
cout << "Enter the day : " << endl;
cin>>day;
total=day;
for(int x=0;x<month-1;x++)
total+=days_per_month[x];
cout << "The number of days in this year till date = " << total << endl;
getch();
}

This program takes in the current day and month as a screen input from the user.
It then calculates the total number of days in the current year till date and outputs it using the 'cout' command.

Program to convert days into years and weeks.

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
int days,years,weeks,num1;
cout << "Enter the number of days : " << endl;
cin>>days;
years=days/365;
num1=days-(years*365);
weeks=days/7;
num1=days-(weeks*7);
cout << days << " days = " << endl;
cout << weeks << " weeks OR " << endl;
cout << years << " years." << endl;
getch();
}

This program takes in the number of days days as a screen input from the user.
It then converts the days into years as well as weeks and outputs it using the 'cout' command.

Program to convert 2-digit octal number into binary number and print it

#include <iostream.h>
#include <conio.h>
void octobin(int);

void main()
{
clrscr();
int a;
cout << "Enter a 2-digit octal number : ";
cin>>a;
octobin(a);
getch();
}
void octobin(int oct)
{
long bnum=0;
int A[6];
//Each octal digit is converted into 3 bits, 2 octal digits = 6 bits.
int a1,a2,quo,rem;
a2=oct/10;
a1=oct-a2*10;
for(int x=0;x<6;x++)
{
A[x]=0;
}
//Storing the remainders of the one's octal digit in the array.
for (x=0;x<3;x++)
{
quo=a1/2;
rem=a1%2;
A[x]=rem;
a1=quo;
}
//Storing the remainders of the ten's octal digit in the array.
for(x=3;x<6;x++)
{
quo=a2/2;
rem=a2%2;
A[x]=rem;
a2=quo;
}
//Obtaining the binary number from the remainders.
for(x=x-1;x>=0;x--)
{
bnum*=10;
bnum+=A[x];
}
cout << "The binary number for the octal number " << oct << " is " << bnum << "." << endl;
}

This program takes in a two-digit octal number a as a screen input from the user.
It then converts the octal number into a binary number and outputs it using the 'cout' command.

Program to find the sum of each row & column of a matrix of size n x m and if matrix is square, find the sum of the diagonals also..

#include <iostream.h>
#include <conio.h>
int main()
{
clrscr();
int A[10][10],m,n,x,y,sum=0;
//Create a Matrix A
cout << "Enter number of rows and columns in Matrix A : \n";
cin>>n>>m;
cout << "Enter elements of Matrix A : \n";
for(x=1;x<n+1;++x)
for(y=1;y<m+1;++y)
cin>>A[x][y];
//Find sum of each row
for(x=1;x<n+1;++x)
{
A[x][m+1]=0;
for(y=1;y<m+1;++y)
A[x][m+1]=A[x][m+1]+A[x][y];
}
//Find sum of each column
for(y=1;y<m+1;++y)
{
A[n+1][y]=0;
for(x=1;x<n+1;++x)
A[n+1][y]+=A[x][y];
}
cout << "\nMatrix A, Row Sum (Last Column)" << " and Column Sum (Last Row) : \n";
for(x=1;x<n+1;++x)
{
for(y=1;y<m+2;++y)
cout << A[x][y] << "     ";
cout << "\n";
}
//Print sum of each column
x=n+1;
for(y=1;y<m+1;++y)
cout << A[x][y] << "     ";
cout << "\n";
if(m==n)
{
for(x=1;x<m+1;x++)
for(y=1;y<n+1;y++)
if(x==y)
sum+=A[x][y];
else
if(y==m-(x+1))
sum+=A[x][y];
}
cout << "Sum of diagonal elements is : " << sum << endl;
getch();
return 0;
}

This program takes in the number of rows (n) and columns (m) as well as the elements as a screen input in a matrix n x m.
It then calculates the sum of each row and each column and outputs it using the 'cout' command.
Also, if it is a square matrix, it calculates the sum of diagonal elements and prints it out

Program to enter an integer and print its total value based on the formula 'x - 1/3!x3 + 1/5!x5 - 1/7!x7 + 1/9!x9'.

#include <iostream.h>
#include <conio.h>
#include <math.h>
int main()
{
clrscr();
float factorial=1;
float num,tot,term,total;
int i,n=20,index,j=1;
cout << "Enter a single-digit integer : \n";
cin>>num;
tot=num;
total=num;
for(i=2,index=3;i<=n;i++,index+=2)
{
for(j=1,factorial=1;j<=index;j++)
factorial*=j;
tot=tot*pow((double)(-1),(double)(2*i-1))*num*num;
term=tot/factorial;
total+=term;
}
cout << "Total = " << total << endl;
getch();
return 0;
}

This program takes in an integer num as a screen input from the user.
It then calculates the total value of the integer based on the formula x - 1/3!x^3 + 1/5!x^5 - 1/7!x^7 + 1/9!x^9.
It then outputs the final answer using the 'cout' command

Program to enter an integer and output it in the reversed form.

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
long int num1,num2,rnum=0;
cout << "Enter an integer : " << endl;
cin>>num1;
num2=num1;
do
{
rnum=rnum*10;
int digit=num1%10;
rnum+=digit;
num1/=10;
}
while(num1);
cout << "The integer you typed is " << num2 << "." << endl;
cout << "The reversed integer is " << rnum << "." << endl;
getch();
}

This program takes in an integer num1 as a screen input from the user.
It then outputs the integer in its reversed form using the 'cout' command.

Program to find the roots of a quadratic equation.

#include <iostream.h>
#include <conio.h>
#include <math.h>
int main()
{
clrscr();
float a,b,c,d,root1,root2;
cout << "Enter the 3 coefficients a, b, c : " << endl;
cin>>a>>b>>c;
if(!a){
if(!b)
cout << "Both a and b cannot be 0 in ax^2 + bx + c = 0" << "\n";
else
{
d=-c/b;
cout << "The solution of the linear equation is : " << d << endl;
}
}
else
{
d=b*b-4*a*c;
if(d>0)
root1=(-b+sqrt(d))/(2*a);
root2=(-b-sqrt(d))/(2*a);
cout << "The first root = " << root1 << endl;
cout << "The second root = " << root2 << endl;
}
getch();
return 0;
}

This program takes in the values of the three coefficients a, b, and c as a screen input from the user.
It then determines the roots of the quadratic equation using the formula ax^2 + bx + c = 0.
The two roots are then outputted using the 'cout' command.

Program to enter salary and output income tax and net salary.

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
int itrate;
float salary,itax,nsalary=0;
cout << "Enter the salary : ";
cin>>salary;
if(salary>15000)
{
itax=salary*30/100;
itrate=30;
}
else if(salary>=7000)
{
itax=salary*20/100;
itrate=20;
}
else
{
itax=salary*10/100;
itrate=10;
}
nsalary=salary-itax;
cout << "Salary = $" << salary << endl;
cout << "Your income tax @ " << itrate << "% = $" << itax << endl;
cout << "Your net salary = $" << nsalary << endl;
getch();
}

This program takes in the salary of the employee as a screen input from the user.
It then deducts the income tax from the salary on the following basis :
30% income tax if the salary is above $15000.
20% income tax if the salary is between $7000 and $15000.
10% income tax if the salary is below $7000.
The salary, income tax and the net salary is then outputted using the 'cout' command

Program to count the number of words and characters in a sentence.

#include <iostream.h>
#include <conio.h>

void main()
{
clrscr();
int countch=0;
int countwd=1;
cout << "Enter your sentence in lowercase: " << endl;
char ch='a';
while(ch!='\r')
{
ch=getche();
if(ch==' ')
countwd++;
else
countch++;
}
cout << "\n Words = " << countwd << endl;
cout << "Characters = " << countch-1 << endl;
getch();
}

This program takes in a sentence as a screen input from the user.
It then determines the number of words and characters in the sentence using the 'WHILE' loop and outputs them using the 'cout' command.

Program to enter the unit reading and output the customer's telephone bill.

#include <iostream.h>
#include <conio.h>
int main()
{
clrscr();
long int units,charge=0;
float total;
const int rent=25;
cout << "Enter the number of units used : ";
cin>>units;
if(units>200)
charge=(units-200)*20+150*40+50*60;
else if(units>50)
charge=(units-50)*40+50*60;
else
charge=units*60;
total=0.01*charge+rent;
cout << "You have used " << units << " units." << endl;
cout << "Your total telephone bill is $" << total;
getch();
return 0;
}

This program takes in the number of units used ('units') as a screen input from the user.
It then calculates the total telephone bill for the customer on the following basis :
A compulsory fee of $25, plus
60 cents per unit for the first 50 units,
40 cents per unit for the next 150 units,
20 cents per unit for anything above 200 units.
It then outputs the bill using the 'cout' command.