Some C++ code snips and toy examples used for teaching basic programming.

aa.cc

#include <iostream>
using namespace std;
int main()
{
  cout << "Hello world!";
}

array_maximum.cc

#include <iostream>
#include <stdio.h>
#include <conio.h>
using namespace std;

void read(int A[],const int k)
{
	int i;
	for(i=0;i<k;i++){
		cout << "A["<<i<<"] = ";
		cin >> A[i];
	}
}
void main()
{
	int i,max;
	const int k = 5;
	int A[k];
	read(A,k);
	max = A[0];
	for (i=0;i<k;i++)
		if(max < A[i])
			max = A[i];
	cout << "\n\n ArrayMax = " << max<<endl;
	_getch();
}		 

array_maximum_recursive.cc

#include <iostream>
#include <stdio.h>
#include <conio.h>
using namespace std;

int maxF(int A[], const int k , int i, int max);

void read(int A[], const int k)
{
	int i;
	for(i=0;i<k;i++){
		cout << "A["<<i<<"] = ";
		cin >> A[i];
	}
}

void main()
{
	int i = 0,max;
	const int k = 5;
	int A[k];
	read(A,k);
	max = A[i];
	cout << "\n\n ArrayMax = " << maxF(A,k,i,max)<< endl;
	_getch();
}

int maxF(int A[], const int k , int i, int max)
{
	if(k == i)
		return max;
	else if( max<A[i])
		return ( maxF( A,k,i+1,A[i] ) );
	else
		return  ( maxF( A,k,i+1,max ) );
}

ax2+bx+c.cc

#include <iostream>
#include <conio.h>
#include <math.h>
using namespace std;
int main()
{
	double a=1;
	double b=2;
	double c=1.5;
	double y;

	while(abs(c*c-2) > 0.0000001) 
	{
		 c = (a+b)/2;
		 y = c*c-2;

    if(y*(a*a-2)<0)
        b = c;
    else if(y*(b*b-2)<0)
        a=c;
	
    //else if(y==0)
     //   cout << c;
	}
	 cout << c;
	_getch();
	return 0;
}

background_color_windows_01.cc

#include <iostream>
#include <conio.h>
#include <Windows.h>
#include <limits>
#ifdef _MSC_VER
#undef max
#endif

using namespace std;
void main()
{
	
	HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
	int color = 0, i;

	SetConsoleTextAttribute(hConsole, FOREGROUND_BLUE | 0x0030);
	cout << "Blue text with green background" << endl;

	for (i = 0; i < 16; i++)
	{
		SetConsoleTextAttribute(hConsole, color); 
		cout << "Hello C++" << endl;
		color++;
	}
	
	cout << "Press Enter to continue..." << endl;
	cin.ignore(numeric_limits<streamsize>::max(), '\n');

	//system("pause");
	//_getche();
}

background_color_windows_02.cc

#include <iostream>
#include <conio.h>
#include <Windows.h>
#include <dos.h>
#include <limits>

#ifdef _MSC_VER
#undef max
#endif

using namespace std;

char far *v = (char far *)0xb8000000;

void printc(char c,int row,int colum,int color){	
	* (v+((160*row)+(2*colum))) = c;	
	* (v+((160*row)+((2*colum)+1))) = color;
}

void main()
{
	int color = 0, i,j;
	
	//v = new char far [100];
	//printc('a',1,1,10);

	HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);

	SetConsoleTextAttribute(hConsole, FOREGROUND_RED | 1000);
	cout << "Blue text with green background" << endl;
	cout << "Hi ok kfhekfffd\n\n\n\n\n";

	for (i = 0,j = 1 ; i < 25; i++, j=3*j)
	{
		SetConsoleTextAttribute(hConsole, color |j); 
		cout << "Hello C++" << endl;
		color++;
	} 
	
	cout << "Press Enter to continue..." << endl;
	cin.ignore(numeric_limits<streamsize>::max(), '\n');

	//system("pause");
	//_getche();
}

huge_int_product_quick_version.cc

/*Zarb*/

//******************************** H E A D E R F I L E ********************************

#include <iostream>

#include <conio.h>

using namespace std;

//******************************** F U N C T I O N ********************************

int mul(int *num1,int *num2,int *num3,int,int);

void calc(char[],char[]);

//******************************** M I A N ********************************

int main()

{

	char cnum1[500],cnum2[500];

	cout<<endl;

	cout<<" Enter num1 : ";

	cin>>cnum1;

	cout<<endl;

	cout<<" Enter num2 : ";

	cin>>cnum2;

	calc(cnum1,cnum2);

	getch();

	return 0;

}

//******************************** C A L C ********************************

void calc(char cnum1[],char cnum2[])

{

    int i,x,limit,len1,len2,len3;

    len1=strlen(cnum1);

    len2=strlen(cnum2);

	int *num1,*num2,*num3;

	num1=(int *)calloc(len1,sizeof(int));

    num2=(int *)calloc(len2,sizeof(int));

	len3=(len1>len2)? len1:len2;

    len3=len3*2;

	num3=(int *)calloc(len3,sizeof(int));

	for(x=0;x<=strlen(cnum1);x++)

        num1[x]=char(cnum1[x])-48;

	for(x=0;x<=strlen(cnum2);x++)

        num2[x]=char(cnum2[x])-48;
	
	len3=mul(num1,num2,num3,len1,len2);

    limit=len3;
	
	for(i=len3;i>=0;i--)

		if(num3[i]==0)

            limit-=1;

        else

		    break;

	cout<<endl<<" Result is : ";
        
	for(i=limit;i>=0;i--)

		cout<<num3[i];

	getch();

}

//******************************** M U L ********************************

int mul(int *num1,int *num2,int *num3,int len1,int len2)

{

	int counter1,counter2,counter3,likenum3,sumnum3,Q,set;

	counter3=0;

	set=-1;

	sumnum3=0;

	for(counter1=len1;counter1>=1;counter1--)

		{

            set++;

            counter3=set;

            Q=0;

            sumnum3=0;

			for(counter2=len2;counter2>=1;counter2--)

				{

					likenum3=num2[counter2-1]*num1[counter1-1]+Q;

					Q=likenum3/10;

					num3[counter3]+=likenum3%10+sumnum3;

					if(sumnum3!=0)

						sumnum3=0;

					if(num3[counter3]>=10)

						{
                 
							sumnum3=num3[counter3]/10;
				 
							num3[counter3]=num3[counter3]%10;

						}

				counter3++;

				}

              num3[counter3]=Q+sumnum3;

  }

    return counter3;

	getch();

}

//******************************** E N D O F P R O G R A M M  ********************************

matrix_saddle_point_1.cc

#include <stdio.h>
#include <conio.h>
int nza(int a[][10],int);
int main()
{
  const int r=10,c=10;
  int a[r][c];
  nza(a,r);
  getch();
  return 0;  
}//end of main()
int nza(int a[][10],int r)
{
  int m=0,n=0,k=0,p=0,t=0,i=0,j=0,mix=0,flag;
  printf("Enter number of rows:");
  scanf("%d",&n);
  printf("Enter number of columns:");
  scanf("%d",&m);
  for(i=0;i<n;i++){
  printf("Enter row %d : ",i);
  for(j=0;j<m;j++)
  scanf("%d",&a[i][j]);}//end of for()
  for(k=0;k<n;k++){
  mix=a[k][t];flag=1;
  for(j=1;j<m;j++)
  if((a[k][j]<mix) && (a[k][j]!=0)){
  mix=a[k][j];
  t=j;p=k;}//end of if()
  for(i=0;i<n;i++){
  if(i!=p)
  if(a[i][t]>mix){
  flag=0;t=0;break;}
  if(i==n-1 && flag==1)
  printf("Noghteye Zin Asbi = %d",mix);
  }//end of for()
  }//end of for()
  if(flag==0)
  return -1;
}//end of nza()    
    

matrix_saddle_point_2.cc

// C++ program to illustrate Saddle point 
/*
* Saddle point in a matrix:
* Given a matrix of n x n size, the task is to find saddle point of the matrix. 
* A saddle point is an element of the matrix such that it is the minimum element in its row and maximum in its column. 
*/
#include <bits/stdc++.h> 
using namespace std; 
  
const int MAX = 100; 
  
// Function to find saddle point 
bool findSaddlePoint(int mat[MAX][MAX], int n) 
{ 
    // Process all rows one by one 
    for (int i = 0; i < n; i++) 
    { 
        // Find the minimum element of row i. 
        // Also find column index of the minimum element 
        int min_row = mat[i][0], col_ind = 0; 
        for (int j = 1; j < n; j++) 
        { 
            if (min_row > mat[i][j]) 
            { 
                min_row = mat[i][j]; 
                col_ind = j; 
            } 
        } 
  
        // Check if the minimum element of row is also 
        // the maximum element of column or not 
        int k; 
        for (k = 0; k < n; k++) 
  
            // Note that col_ind is fixed 
            if (min_row < mat[k][col_ind]) 
                break; 
  
        // If saddle point is present in this row then 
        // print it 
        if (k == n) 
        { 
           cout << "Value of Saddle Point " << min_row; 
           return true; 
        } 
    } 
  
    // If Saddle Point not found 
    return false; 
} 
  
// Driver code 
int main() 
{ 
    int mat[MAX][MAX] = {{1, 2, 3}, 
                        {4, 5, 6}, 
                        {7, 8, 9}}; 
    int n = 3; 
    if (findSaddlePoint(mat, n) == false) 
       cout << "No Saddle Point "; 
    return 0; 
} 

matrix_sum.cc

/* Matrix sum Project 
   By : Morteza Zakeri 902
   Date : 90/12/05
   ::Run this program with Microsoft Visual Stdio 2010 (Visual C++ 10)
*/

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

using namespace std;

void main()
{
	const int k = 100;
	int m ,n, i, j;
	float a[k][k]={0} , b[k][k]={0};
	cout << "\n ::Enter number of M1 rows: ";
	cin >> m;
	cout << "\n ::Enter number of M1 columns: ";
	cin >>n;
	cout << "\n M2 has " << m << " Row & " << n <<" Column, too!\n ";
	cout << "\n::Enter M1 data:\n\n";
	for(i = 0; i < m; i++){
		for(j = 0; j < n; j++ ){
			cout << "\tA["<<i+1<<"]["<<j+1<<"]: ";
			cin >> a[i][j];
		}
		cout <<"\n";
	}//M1 
	cout << "\n::Enter M2 data:\n\n";
	for(i = 0; i < m; i++){
		for(j = 0; j < n; j++ ){
			cout << "\tB["<<i+1<<"]["<<j+1<<"]: ";
			cin >> b[i][j];
		}
		cout <<"\n";
	}//M2
	for(i = 0; i < m; i++){
		for(j = 0; j < n; j++ ){
			cout << "\tA+B["<<i+1<<"]["<<j+1<<"] = ";
			cout << a[i][j] + b[i][j];
			cout <<"\n";
		}
		cout <<"\n";
	}//M1 + M2
	cout << "Press a key to Exit ... ";
	_getch();

}

maximum_gap_recursive.cc

#include <iostream>
#include <stdio.h>
#include <conio.h>
using namespace std;

int maxF(int A[], const int k , int i, int max);

void read(int A[], const int k)
{
	int i;
	for(i=0;i<k;i++){
		cout << "A["<<i<<"] = ";
		cin >> A[i];
	}
}

void main()
{
	int i = 0,max;
	const int k = 5;
	int A[k];
	read(A,k);
	max = A[i];
	cout << "\n\n ArrayMax = " << maxF(A,k,i,max)<< endl;
	_getch();
}

int maxF(int A[], const int k , int i, int max)
{
	if(k == i)
		return max;
	else if( max<(A[i+1]-A[i]))
		return ( maxF( A,k,i+1,A[i+1]-A[i] ) );
	else
		return  ( maxF( A,k,i+1,max ) );
}

multinomial_products.cc

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

using namespace std;

void main(){
	int i,j,k;
	cout <<"Enter 1:";
	int A[5], B[4], C[8];

	for(i = 0; i<8; i++)
		C[i] = 0;

	for(i = 0; i<5; i++){
		cout << "Enter " <<i<<" ^x : ";
		cin >>A[i];
	}

	cout <<"Enter 2:";
	for(i = 0; i<4; i++){
		cout << "Enter " <<i<<" ^x : ";
		cin >>B[i];
	}
	for(i = 0;i<5; i++)
		for(j=0; j<4 ;j++)
			C[i+j]+=A[i]*B[j];

	for(i = 7; i>=0; i--)
		cout << C[i] << "X^" <<i<<" + ";
	_getch();

}

numbers_1.cc

/* Numbers1 Project 
   By : Morteza Zakeri 902
   Date : 90/12/10
   ::Run this program with Microsoft Visual Stdio 2010 (Visual C++ 10)
*/

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

using namespace std;

void main()
{
	
	int i=0, j, k,m, n, a=0;
	cout << "::Enter a Number: ";
	cin >> n;
	system("cls");
	a = n;
	for (i = a,m = 0; i>0; m++,i--){
		for (j=0 ; j < m ; j++)
			cout << " ";
		for (k=2*i+1; k > 2 ; k--)
			cout << i ;
		cout << "\n";
		a++;
	}
	
	a = n;
	for (i = 1; i <= n; i++){
		for (j=a-1 ; j > 0 ; j--)
			cout << " ";
		for (k=2 ; k < 2*i+1 ; k++)
			cout << i ;
		cout << "\n";
		a--;
	}
	_getch();

}

numbers_2.cc

/* Numbers2 Project 
   By : Morteza Zakeri 902 
   Date : 90/12/10
   ::Run this program with Microsoft Visual Stdio 2010 (Visual C++ 10)
*/

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

using namespace std;

void main()
{
	
	int i, j, k, m, n, a;
	cout << "::Enter a Number: ";
	cin >> n;
	system("cls");
	a = n;
	i = a;
	m = 0;
	while(i){
		j=0;
		while(j<m){
			cout << " ";
			j++;
		}
		k=2*i+1;
		while(k>2){
		cout << i;
		k--;
		}
		cout << "\n";
		a++;
		m++;
		i--;
	}

	a = n;
	i = 1;
	while(i<=n){
		j=0;
		j = a-1;
		while(j){
			cout << " ";
			j--;
		}
		k=2;
		while(k<2*i+1){
			cout << i;
			k++;
		}
		cout << "\n";
		a--;
		i++;
	}
		
	_getch();

}

persian_calendar.cc

#include <conio.h>
#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{
    int i,j,k,l,m=31;
    cout<<"\t\t\t\tWeek Menu"<<endl<<endl;
    cout<<"\t\t1-Sat\t2-Sun\t3-Mon\t4-Tus\t5-Wed\t6-Tur\t7-Fri\n";
    cout<<"\n\t\t\t  Enter First day of year : ";
    cin>>l;
    //system("cls");
    for(i=1;i<=12;i++){
        cout<<endl<<endl;
        switch(i){
              case 1:
              cout<<"\t\t\t  ***Farvardin***"<<endl;
              break;
              case 2:
              cout<<"\t\t\t  ***Ordibehesht***"<<endl;
              break;
              case 3:
              cout<<"\t\t\t  ***Khordad***"<<endl;
              break;
              case 4:
              cout<<"\t\t\t  ***Tir***"<<endl;
              break;
              case 5:
              cout<<"\t\t\t  ***Mordad***"<<endl;
              break;
              case 6:
              cout<<"\t\t\t  ***Shahrivar***"<<endl;
              break;
              case 7:
              cout<<"\t\t\t  ***Mehr***"<<endl;
              break;
              case 8:
              cout<<"\t\t\t  ***Aban***"<<endl;
              break;
              case 9:
              cout<<"\t\t\t  ***Azar***"<<endl;
              break;
              case 10:
              cout<<"\t\t\t  ***Day***"<<endl;
              break;
              case 11:
              cout<<"\t\t\t  ***Bahman***"<<endl;
              break;
              case 12:
              cout<<"\t\t\t  ***Esfand***"<<endl;
              break;
       }//end of switch
       if(i==7)
          m=30;
       if(i==12)
          m=29;
       cout<<"\n\tSat\tSun\tMon\tTus\tWed\tTur\tFri\n";
       for(k=1;k<l;k++){
          cout<<"\t";
    }//end of for
       for(j=1;j<=m;j++){
       switch(l){
             case 1:
             cout<<"\t"<<j;
             l++;
             break;
             case 2:
             cout<<"\t"<<j;
             l++;
             break;
             case 3:
             cout<<"\t"<<j;
             l++;
             break;
             case 4:
             cout<<"\t"<<j;
             l++;
             break;
             case 5:
             cout<<"\t"<<j;
             l++;
             break;
             case 6:
             cout<<"\t"<<j;
             l++;
             break;
             case 7:
             printf("\t%d\n",j);
             l=1;
             break;
       }//end of switch
       }//end of for
    getch();
    }//end of for
}//end of main

recursive_print_hello.cc

#include <iostream>
#include <stdio.h>
#include <conio.h>
using namespace std;
void h(int n)
{
	if(n <= 1)
		cout << "Hello\t";
	else
		for (int i = 0 ; i <n ; i++)
			h(i);
}
void main()
{
	h(5);
	_getch();
}

starts.cc

/* Stars3 Project 
   By : Morteza Zakeri 902
   Date : 90/12/05
   ::Run this program with Microsoft Visual Stdio 2010 (Visual C++ 10)
*/

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

using namespace std;

void main()
{
	int i, j, k, n, a;
	cout << "Enter a Number: ";
	cin >> n;
	a = n;
	system("cls");
	for (i = 1; i <= n; i++){
		for (j=a-1 ; j > 0 ; j--)
			cout << " ";
		for (k=2 ; k < 2*i+1 ; k++)
			cout << "*";
		cout << "\n";
		a--;
	}
	_getch();
}

static_field_in_class.cc

#include <iostream>
#include <stdio.h>
#include <conio.h>
using namespace std;
class Example{
private:
	int x;
public:
	static int c;
	Example(){c++;cout <<c<<"  " ;}
	~Example(){c--;cout << c<< " ";}
};
int Example::c =0;

void main()
{
	Example Obj1[10];
	_getch();
}

string_functions.cc

/* Stars3 Project 
   By : Morteza Zakeri 902
   Date : 90/12/05
   ::Run this program with Microsoft Visual Stdio 2010 (Visual C++ 10)
*/

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

using namespace std;


void capitalize();
void repeat();
void threeletter();
void wordy();

char word[50];

void main()
{
//char word[50];

int flag=1,i=0,s;
cout<<"Please enter your string: "<<"\n";

/*while(flag)
	{
	word[i]=getche();
	i++;
	if(word[i-1]=='\r')
		flag=0;
	} */

gets(word);

//gets(word);
cout<<"\n"<<"Please select one this item: ";
cout<<"\n\n1.Capitalize          2.counting the repeat item";
cout<<"\n3.Three letter word     4.word that start ehit 'y'";
cin>>s;
if(s==1) {
	capitalize();

}
else if(s==2)
	repeat();
else if(s==3)
	threeletter();
else if(s==4)
	wordy();
cout <<endl;
system("pause");
} 

//****************************
void capitalize()
{
for(int j=0;j<strlen(word);j++)
	{
	if(word[j]>='a' && word[j]<='z')
		word[j]= word[j]-32;
	}
for(int j=0;j<=strlen(word);j++)
	cout<< word[j];
}
//***********************************

// this function is not still word correct!!!
void repeat()
{
int counter = 0;
for(int j=0;j<strlen(word);j++)
	{
	for(int k=0;k<strlen(word);k++)
		if(word[j] == word[k])
			counter++;
	cout << word[j] << "  ->  " << counter <<endl;
	counter = 0;
	}
}

//************************************
void threeletter()
{
int counter = 0;
for(int j=0; j<strlen(word); j++)
	{
	counter++;
	if(word[j]==' ' || j==strlen(word)-1)
		{
		if(counter==4 || j==strlen(word)-1)
			for(int k=j-3;k<=j;k++)
				cout<<word[k];
		counter=0;
		}
	}
}
//***********************************
void wordy()
{

for(int j=0; j< strlen(word); j++)
	{
	if(word[j]=='y' || word[j]=='Y')
	{
		int i=j;
		if(word[i-1]==' '|| i==0) {
		while(word[i] != ' ' && i<strlen(word))
		{
			cout << word[i++];
		}
		cout <<	 endl;
		}	
	}
	}
}

sum_digits.cc

#include <iostream>
#include <stdio.h>
#include <conio.h>
using namespace std;

void main()
{
	int n, sum = 0;
	cin >> n;
	while(n){
		 sum += n%10;
		 n /= 10;
	}
	cout << sum;
	_getch();
}		 

sum_digits_recursive.cc

#include <iostream>
#include <stdio.h>
#include <conio.h>
using namespace std;

int sumDigit(int n)
{
	if(n == 0)
		return 0;
	else 
		return(n%10 + sumDigit(n/10));
}

void main()
{
	int n;
	cin >> n;
	cout << sumDigit(n);
	_getch();
}	

wait_line_1.cc

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

    
int main ()
{
	int i,j,k;
	for(i=0; i<=25;i++){
	for(k=1;k<15;k++){
		printf("%c",176);
		for(j=0;j<25000000;j++);
	}
	for(k=15;k<=30;k++){
		printf("%c",177);
		for(j=0;j<30000000;j++);
	}
	for(k=31;k<=50;k++){
		printf("%c",219);
		for(j=0;j<30000000;j++);
	}
	for(k=51;k<=66;k++){
		printf("%c",177);
		for(j=0;j<30000000;j++);
	}
	for(k=67;k<=80;k++){
		printf("%c",176);
		for(j=0;j<30000000;j++);
	}  
	}
	_getch();
	return 0;
}

wait_line_2.cc

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

    
int main ()
{
	int i,j,k;
	for(i=0; i<=2;i++){
	for(k=1;k<15;k++){
		printf("%c",176);
		for(j=0;j<30000000;j++);
	}
	for(k=15;k<=30;k++){
		printf("%c",177);
		for(j=0;j<25000000;j++);
	}
	for(k=31;k<=50;k++){
		printf("%c",219);
		for(j=0;j<20000000;j++);
	}
	for(k=51;k<=66;k++){
		printf("%c",177);
		for(j=0;j<15000000;j++);
	}
	for(k=67;k<=80;k++){
		printf("%c",176);
		for(j=0;j<10000000;j++);
	}  
	}
	_getch();
	return 0;
}

welcome.cc

//First program with C++;
#include <stdio.h>
#include <conio.h>
#include <iostream>
using namespace std;
int main()
{
	int sum,x,y;
        cout << "Welcome to C++! ";
	cout << "Enter number 1:  ";
	cin >> x;
	cout << "Enter number 2:  ";
	cin >> y;
	sum = x + y;
	cout << "\nSUM = "<<sum<<"\n\nPress any key to exit... ";
	getch();
}