Files
//Write a program to store squares of numbers
from 1 to 10
//in a file
void main(void)
{
int k;
ofstream ofp;
ofp.open("mosalah.txt");
for(k = 1 ; k <= 10 ; k++)
ofp << k << "\t" << k*k << "\n";
ofp.close();
}
Write a program to read a file mydata
//then, print the data inside it
void main(void)
{
ifstream ifp;
ifp.open("mydata.txt");
if(ifp.is_open() == true) cout << "Input file is opened \n";
else { cout << "Error, input file could not be
opened \n"; return; }
int a , b;
while(ifp >> a)
{
ifp >> b;
cout << a << "\t" << b << "\n";
}
getch();
}
Write a program to store squares of even
numbers from 6 to 40
//in a file called salah
//Then, reopen the file and print its contents
void main(void)
{
int k;
ofstream toto;
toto.open("salah.txt");
for(int k = 6 ; k <= 40 ; k=k+2)
toto << k << "\t" << k*k << "\n";
toto.close();
}
*/
/*
void main(void)
{
ifstream ifp;
ifp.open("salah.txt");
if(ifp.is_open() == true) cout << "Input file is opened \n";
else { cout << "Error, input file could not be opened \n"; getch();
return; }
int a , b;
while(ifp >> a)
{
ifp >> b;
cout << a << "\t" << b << "\n";
}
getch();
}
// Write a program to print contents of the
previous
//file squares.txt
/*
void main(void)
{
FILE *pf2;
pf2 = fopen("salah.txt","r");
if(pf2 == NULL)
{
cout << "ERROR; File can not be opened\n";
return;
}
int k , n , m;
for(k = 1 ; k <= 9 ; k++)
{
fscanf(pf2,"%d %d ",&n,&m);
printf("%d \t %d \n",n,m);
}
fclose(pf2);
}
*/
//Write a program to generate random
unrepeated numbers with values less
//than 100. Store the generated numbers in a
file called
//"random_numbers.txt". If the generated
number is equals
//to zero, stop the program.
/*
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <ctime>
using namespace std;
int main() {
srand(time(NULL));
int nums[99];
// 1. 99 إلى1 نمأل المصفوفة من
for (int i = 0; i < 99; i++) {
nums[i] = i + 1;
}
// 2. نعملshuffle ()تبديل عشوائي
for (int i = 0; i < 99; i++) {
int j = rand() % 99;
// تبادل العناصر
int temp = nums[i];
nums[i] = nums[j];
nums[j] = temp;
}
// 3. نكتب األرقام في الملف
ofstream outFile("random_numbers.txt");
for (int i = 0; i < 99; i++) {
outFile << nums[i] << "\n";
cout << nums[i] << "\t";
}
outFile.close();
return 0;
}
If repeated
void main(void)
{
srand(time(NULL));
// srand(3);
ofstream ofp;
ofp.open("random_numbers.txt");
int num ;
do{
num = rand() % 100;
cout << num << "\t";
ofp << num << "\n";
}while(num != 0);
ofp.close();
getch();
}
//Write a program to read integer numbers from
a file called
//"random_numbers.txt" store odd numbers in
a file called
//"odd_numbers.txt" and even numbers in
//another file called "even_numbers.txt".
/*
void main(void)
{
ofstream oddp , evenp;
ifstream ifp;
ifp.open("random_numbers.txt");
oddp.open("odd_numbers.txt");
evenp.open("even_numbers.txt");
int num;
while(ifp)
{
ifp >> num ;
if(num % 2 == 0) evenp << num << "\n";
else oddp << num << "\n";
cout << num << "\t";
}
ifp.close();
oddp.close();
evenp.close();
getch();
}
//Write a program to copy a file calld
"random_numbers.txt"
//into another file called "mydata.txt"
/*
void main(void)
{
FILE *pf1 , *pf2;
char ch;
pf1 = fopen("random_numbers.txt","r");
if(pf1 == NULL)
{
printf( "ERROR; random_numbers.txt file can not be opened\n");
return;
}
pf2 = fopen("mydata.txt","w");
if(pf2 == NULL)
{
printf("ERROR; mydata.txt file can not be opened\n");
return;
}
while((ch = getc(pf1)) != EOF )
{
// ch = getc(pf1);
// if(ch == EOF) break;
// ch++;
putc(ch,pf2);
cout << ch;
}
fclose(pf1);
fclose(pf2);
}
*/
//Write a program to read a key number.
//Count the number of times this key
//number exists in a file called
"odd_numbers.txt"
/*
void main(void)
{
ifstream ifp("odd_numbers.txt");
int key , n , counter = 0 ;
if(!ifp)
{
printf( "ERROR; random_numbers.txt file can not be opened\n");
return;
}
cout << "Enter key number: ";
cin >> key;
while(ifp)
{
ifp >> n;
if(n == key) counter++;
cout << n << " ";
}
cout << "\n The number " << key << " is found " << counter << " times \n";
ifp.close();
getch();
}
//Write a program to read numbers from a file
called
//"random_numbers.txt"
//sort these numbers, store the numbers after
sorting in a
//file called sorted_random_numbers.txt
/*
void main(void)
{
int a , b , size , *arr , temp;
ifstream ifp;
ofstream ofp;
ifp.open("random_numbers.txt");
if(ifp.is_open() == true) cout << "Input file is opened \n";
else { cout << "Error, input file could not be opened \n"; return; }
size = 0;
while(ifp >> a) { cout << a << "\t" ; size++; }
ifp.close();
arr = new int[size];
ifp.open("random_numbers.txt");
for(a = 0 ; ifp >> arr[a] ; a++) continue;
// for(a = 0 ; a < size ; a++) ifp >> arr[a];
ifp.close();
for(a = 0 ; a <= size -2 ; a++)
for(b = a+1 ; b <= size-1 ; b++)
if(arr[a] > arr[b])
{ temp = arr[a] ; arr[a] = arr[b] ; arr[b] = temp ; }
cout << "\n\n";
ofp.open("sorted_random_numbers.txt");
for(a = 0 ; a < size ; a++)
{
ofp << arr[a] << "\n";
cout << arr[a] << "\t";
}
ofp.close();
}
*/
//Write a program to read numbers from a file
called
//"random_numbers.txt"
//delete repeated numbers, store the numbers
after deleting in a
//file called unrepeated_data.txt
void main(void)
{
int a , b , size , *arr , temp;
ifstream ifp;
ofstream ofp;
ifp.open("random_numbers.txt");
if(ifp.is_open() == true) cout << "Input file is opened \n";
else { cout << "Error, input file could not be opened \n"; return; }
size = 0;
while(ifp >> a) { cout << a << "\t" ; size++; }
ifp.close();
arr = new int[size];
ifp.open("random_numbers.txt");
a = 0;
while( ifp >> temp)
{
for(b = 0 ; b < a ; b++)
if(temp == arr[b]) break;
if(b == a) { arr[a] = temp; a++; }
}
ifp.close();
cout << "\n\n";
ofp.open("unrepeated_random_numbers.txt");
for(b = 0 ; b < a; b++)
{
ofp << arr[b] << "\n";
cout << arr[b] << "\t";
}
ofp.close();
}
