C

  #include <stdio.h> #include <stdlib.h> int main () {     int * ptr ;     int i ;     int n ;       printf ( "enter n: \n " );       scanf ( " %d " , & n );     ptr = ( int * ) malloc ( 10 * sizeof ( int ));     for ( i = 1 ; i <= 10 ; i ++ )    {       ptr [ i ] = n * i ; printf ( " %d x %d = %d \n " , n , i , ptr [ i ]);    }             ptr [ i ] = realloc ( ptr , 15 * sizeof ( int ));     printf ( "after reallocation \n " );     for ( i = 1 ; i <= 15 ; i ++ )    {             ptr [ i ] = n * i ;       printf ( " %d x %d = %d \n " , n , i , ptr [ i ]);    }       free ( ptr ); }

  #include <stdio.h> #include <stdlib.h> int main () {     int * ptr ;     int i ;     ptr = ( int * ) malloc ( 5 * sizeof ( int ));     for ( i = 0 ; i < 5 ; i ++ )    {       printf ( "enter element %d : \n " , i + 1 );       scanf ( " %d " , & ptr [ i ]);    }         for ( i = 0 ; i < 5 ; i ++ ) {     printf ( " %d element is: %d \n " , i + 1 , ptr [ i ]); }     ptr = realloc ( ptr , 10 * sizeof ( int ));     for ( i = 0 ; i < 10 ; i ++ )    {       printf ( "enter %d element:" , i + 1 );       scanf ( " %d " , & ptr [ i ]);    }         for ( i = 0 ; i < 10 ; i ++ ) {     printf ( " %d element is: %d \n " , i + 1 , ptr [ i ]); } free ( ptr ); }

  #include <stdio.h> #include <stdlib.h> int main () {     int * ptr ;     int n ;     printf ( "enter n:" );     scanf ( " %d " , & n );     ptr = ( int * ) calloc ( n , sizeof ( int ));     for ( int i = 0 ; i < n ; i ++ )    {       printf ( "enter element %d : \n " , i + 1 );       scanf ( " %d " , & ptr [ i ]);    }       for ( int i = 0 ; i < n ; i ++ ) {     printf ( " %d element is: %d \n " , i + 1 , ptr [ i ]); } return 0 ; }

    #include <stdio.h>   #include <stdlib.h>       int main ()  {     float * ptr ;     ptr = ( float * ) malloc ( 6 * sizeof ( int ));     for ( int i = 0 ; i < 6 ; i ++ )    {       scanf ( " %f " , & ptr [ i ]);    }       for ( int i = 0 ; i < 6 ; i ++ ) {     printf ( "elemts are: %f \n " , ptr [ i ]); }  }

    #include <stdio.h>   #include <stdlib.h>       int main ()  {     int * ptr ;     ptr = ( int * ) malloc ( 6 * sizeof ( int ));     for ( int i = 0 ; i < 6 ; i ++ )    {       scanf ( " %d " , & ptr [ i ]);    }       for ( int i = 0 ; i < 6 ; i ++ ) {     printf ( "elemts are: %d \n " , ptr [ i ]); }  }

  #include <stdio.h> #include <stdlib.h> #include <time.h> void choice ( char you , char me )  {     if ( you == me )      {         printf ( "GAME DRAW! \n " );      }       else   if ( you == 'r' && me == 'p' )      {         printf ( "YOU LOST! \n " );      }       else   if ( you == 'r' && me == 's' )      {         printf ( "YOU WON! \n " );      }       else   if ( you == 'p' && me == 'r' )      {         printf ( "YOU WON! \n " );      }       else   if ( you == 'p' && me == 's' )      {         printf ( "YOU WON! \n " );      }       else   if ( you =...

  #include <stdio.h> #include <stdlib.h> #include <time.h> int main () { int n , guess , count = 1 ;     srand ( time ( 0 ));       n = rand () % 100 ;     for ( count = 1 ; guess != n ; count ++ )     {         printf ( "enter number: \n " );         scanf ( " %d " , & guess );         if ( guess > n )         {             printf ( "try a smaller number \n " );         }         else if ( guess < n )         {             printf ( "try a higher number \n " );         }         else {             printf ( "you guessed it right in %d attempts \n " , count );         }     }     return 0 ; }

  #include <stdio.h> #include <stdlib.h> #include <time.h> int main () {     srand ( time ( NULL ));     printf ( " %d " , rand ());     return 0 ; }

#include <stdio.h> int main () {     FILE * ptr ;     FILE * fptr ;     int n ;     ptr = fopen ( "double.txt" , "r" );     fscanf ( ptr , " %d " , & n ); fclose ( ptr ); fptr = fopen ( "double.txt" , "w" ); fprintf ( fptr , " %d " , 2 * n ); fclose ( fptr ); }

  #include <stdio.h> int main () {     FILE * ptr ;           FILE * fptr ;           fptr = fopen ( "write.txt" , "w" );     ptr = fopen ( "ab.txt" , "r" );     char c ;               c = fgetc ( ptr );     while ( c != EOF )     {           fputc ( c , fptr );                   fputc ( c , fptr );                   c = fgetc ( ptr );     }     fclose ( ptr );         fclose ( fptr ); }

  #include <stdio.h> int main () {     FILE * ptr ;     ptr = fopen ( "table.txt" , "w" );     int n ;     printf ( "enter n: \n " );     scanf ( " %d " , & n );     for ( int i = 1 ; i <= 10 ; i ++ )     {         fprintf ( ptr , " %d x %d = %d \n " , n , i , n * i );     }     fclose ( ptr );     return 0 ; }

  #include <stdio.h> int main () {     FILE * ptr ;     ptr = fopen ( "hel.txt" , "r" ); char c ; while ( c != EOF ) {     c = getc ( ptr );     printf ( " %c " , c ); } fclose ( ptr ); return 0 ;     }

#include <stdio.h> int main () {     FILE * ptr ;     ptr = fopen ( "hel.txt" , "w" );     fputc ( 'a' , ptr );         fputc ( 'b' , ptr );     fputc ( 'h' , ptr );     fputc ( 'i' , ptr );     fclose ( ptr );     return 0 ; }

#include <stdio.h> int main () {     FILE * ptr ;     ptr = fopen ( "ab.txt" , "r" );         printf ( " %c " , fgetc ( ptr ));         printf ( " %c " , fgetc ( ptr ));     printf ( " %c " , fgetc ( ptr ));     printf ( " %c " , fgetc ( ptr )); fclose ( ptr ); return 0 ; }

  #include <stdio.h> int main () {     FILE * ptr ;     char c [ 100 ] = "abhi" ;     ptr = fopen ( "ab.txt" , "w" ); fprintf ( ptr , " %s " , c ); fclose ( ptr ); return 0 ; }

  #include <stdio.h> int main () {     FILE * ptr ; int n = 100 ;     ptr = fopen ( "ab.txt" , "w" );     fprintf ( ptr , " %d " , n );     fclose ( ptr );     }

  #include <stdio.h> int main () {     FILE * ptr ;     int n1 , n2 ;     ptr = fopen ( "ab.txt" , "r" );     if ( ptr == NULL )     { printf ( "file doesnot exist" );     }     else {         fscanf ( ptr , " %d " , & n1 );                 fscanf ( ptr , " %d \n " , & n2 );                 fclose ( ptr );         printf ( "n1: %d \n " , n1 );                 printf ( "n2: %d " , n2 );     }     return 0 ; }

  #include <stdio.h> int main () { FILE * ptr ; char c ; ptr = fopen ( "ab.txt" , "r" ); fscanf ( ptr , " %c " , & c ); printf ( " %c " , c ); fscanf ( ptr , " %c " , & c ); printf ( " %c " , c ); fscanf ( ptr , " %c " , & c ); printf ( " %c " , c ); fscanf ( ptr , " %c " , & c ); printf ( " %c " , c ); fclose ( ptr ); return 0 ; }

  #include <stdio.h> int main () {     FILE * ptr ;     int n ;     ptr = fopen ( "ab.txt" , "r" ); fscanf ( ptr , " %d " , & n ); printf ( "the value of n is %d " , n ); return 0 ; }

  #include <stdio.h> typedef struct timestamp {     int date , month , year , hours , minutes , seconds ; } time ; int display ( time d ); int timecmp ( time d1 , time d2 ); int main () {     time d1 = { 11 , 3 , 2004 , 3 , 45 , 56 };     time d2 = { 11 , 3 , 2004 , 3 , 30 , 44 }; display ( d1 ); display ( d2 ); int a = timecmp ( d1 , d2 ); printf ( "dater comparison returns %d " , a ); } int display ( time d ) {     printf ( " %d / %d / %d / %d : %d : %d \n " , d . date , d . month , d . year , d . hours , d . minutes , d . seconds ); } int timecmp ( time d1 , time d2 ) {     if ( d1 . date > d2 . date )     {         return 1 ;     }       if ( d1 . date < d2 . date )     {         return - 1 ;     }       if ( d1 . month > d2 . month )     {         return ...

  #include <stdio.h>   typedef struct complex {     int x , y ; } comp ; void display ( comp c ); int main () {     comp c [ 5 ];     for ( int i = 0 ; i < 5 ; i ++ )     {         printf ( "enter real part:" );         scanf ( " %d " , & c [ i ]. x );         printf ( "enter imaginary part:" ); scanf ( " %d " , & c [ i ]. y );     }     for ( int i = 0 ; i < 5 ; i ++ ) { display ( c [ i ]); }     } void display ( comp c ) {               printf ( "real part is: %d \n " , c . x );                 printf ( "imaginary part is: %d \n " , c . y );     }

  #include <stdio.h> struct complex {     int x , y ; }; int main () {     struct complex c1 = { 3 , 5 };     struct complex * ptr =& c1 ;     printf ( "real part: %d \n " , ptr -> x ); printf ( "imaginary part: %d \n " , ptr -> y ); }

  #include <stdio.h> typedef struct vector {     int x ;     int y ; } v ; void sum ( struct vector v1 , struct vector v2 , struct vector v3 ); int main () {     struct vector v1 = { 6 , 7 };     v v2 = { 4 , 9 }; v v3 = { 0 }; sum ( v1 , v2 , v3 ); } void sum ( struct vector v1 , struct vector v2 , struct vector v3 ) {     v3 . x = v1 . x + v2 . x ;     v3 . y = v1 . y + v2 . y ;     printf ( "sum of x: %d \n " , v3 . x );     printf ( "sum of y: %d \n " , v3 . y );     printf ( "v3: %d , %d \n " , v3 . x , v3 . y ); }

  #include <stdio.h> struct student {     int rollno ;     char name [ 50 ];     float cgpa ; }; int main () { struct student std [ 5 ]; printf ( "enter student 1 details: \n " );     printf ( "enter rollno: \n " ); scanf ( " %d " , & std [ 0 ]. rollno ); printf ( "enter name: \n " ); scanf ( " %s " , std [ 0 ]. name ); printf ( "enter cgpa: \n " ); scanf ( " %f " , & std [ 0 ]. cgpa ); printf ( "enter student 2 details: \n " );       printf ( "enter rollno: \n " ); scanf ( " %d " , & std [ 1 ]. rollno ); printf ( "enter name: \n " ); scanf ( " %s " , std [ 1 ]. name ); printf ( "enter cgpa: \n " ); scanf ( " %f " , & std [ 1 ]. cgpa ); printf ( "enter student 3 details: \n " );       printf ( "enter rollno: \n " ); scanf ( " %d " , & std [ 2 ]. rollno ); printf ( "enter name: \n ...

  #include <stdio.h> #include <string.h> typedef struct student { int rollno ; char   name [ 50 ]; int marks ; } std ; int main () { std s1 ; std * ptr ; ptr =& s1 ; ptr -> rollno = 71 ; strcpy ( ptr -> name , "abhi" ); ptr -> marks = 99 ; std s2 ; std * p ; p =& s2 ; p -> rollno = 5468 ; strcpy ( p -> name , "kaala" ); p -> marks = 00 ; show ( s1 ); display ( s2 ); } void show ( std s1 ) { printf ( "rollno: %d \n " , s1 . rollno ); printf ( "name: %s \n " , s1 . name ); printf ( "marks: %d \n " , s1 . marks ); } void display ( std s2 ) {   printf ( "rollno: %d \n " , s2 . rollno ); printf ( "name: %s \n " , s2 . name ); printf ( "marks: %d \n " , s2 . marks ); }  

  #include <stdio.h> struct student {     int rollno ;     char   name [ 50 ];     int marks ; }; int main () { struct student s1 = { 43 , "abhi" , 99 }; struct student s2 = { 34 , "gani" , 85 }; struct student s3 = { 71 , "ravi" , 77 }; printf ( "rollno : %d \n " , s1 . rollno ); printf ( "name : %s \n " , s1 . name ); printf ( "marks: %d \n " , s1 . marks ); printf ( "rollno: %d \n " , s2 . rollno ); printf ( "marks: %d \n " , s2 . marks ); printf ( "name : %s \n " , s2 . name ); printf ( "rollno : %d \n " , s3 . rollno ); printf ( "name : %s \n " , s3 . name ); printf ( "marks: %d \n " , s3 . marks ); }