Final Exam 2 (20%)

Question

A string p is a prefix of a string s if the leading characters of s are identical to p. For example, "abc" is a prefix of "abcde". Develop a function prefix that checks if a C string p is a prefix of another C string s.

p是s的前綴若s開頭的一段字串等於p。例如，"abc"是"abcde"的前綴。寫一個程式 判斷字串p是否字串s的前綴。

Example input 1:

abc
abcde

Example output 1:

abc is a prefix of abcde

 

Example input 2:

bc
abcde

Example output 2:

bc is not a prefix of abcde

 

Answer 1

Hidden content!
   * * ** * *   *
  *** ** **    * * 

int main()
{
* ***  *    *  * char   ** **  *
  ** * **   * int i,c=0;
   *     *  * *** *  *    * *  * ***    ***  
 * **   *   *** * *   *  * *      ****  ***     
 ****  *   **  *    * ****      
   *  **    * *** {
** *  ***   *   *   *** *   ***** *  *  ***
  * *  *    **  **          {
** *    ****  * *  *    * *    *  ** * ** ****   * ***   **** *    *   * 
**  *  *** *   *  *** *      ** **   *  *     ***** * *  *   * {
*    **               * ***   *  *  * ** c=0;
 *** ** * * * **  *  *** *  *  * * *  *  *    **** ** *** }
*   *       *  *  ***   *   *   ***  ***     else ****   * **** ** ***  ** ***   
     * * * ***   *     * ** ** * * * ***  **      **  ***  **  * {
 ***   *  **  ** *   ** *   ****  ** **  ** *** * * ** *  * * *  * *  *  *  c++;
 *** *      ** *    *    **    *       ****   **** ** *    ** }
  **  *   * **    *   ***  ***  * }
*  * **       **  
   *  ** *   *  if(c==0)
*   ** ** *** **      * *  * ***       ***  ** is not a prefix of  **  ** *  
 *     *  *    *  else
 **** *   * * *** ** *    ***   *** **    * is a prefix of *  *  *   
* ****  ** *   * }
    *  * *  * return 0;
}

Comments

prog.c: In function 'main':
prog.c:8:11: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[10]' [-Wformat=]
   scanf("%s",&a);
           ^
prog.c:9:11: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[10]' [-Wformat=]
   scanf("%s",&b);
           ^

---

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output

---

Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output

---

Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output

---

prog.c: In function 'main':
prog.c:10:6: warning: implicit declaration of function 'stlen' [-Wimplicit-function-declaration]
   if(stlen(b)>strlen(a))
      ^~~~~
/tmp/ccnE3ufV.o: In function `main':
prog.c:(.text+0x5b): undefined reference to `stlen'
collect2: error: ld returned 1 exit status

---

Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output

---

Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output

---

Case 0: Wrong output
Case 1: Correct output
Case 2: Wrong output

---

Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output

---

Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output

---

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output

---

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

Answer 2

Hidden content!
**** **  ****  
*** *  * ** * *  ***
int main()
{
  *****   **** **  * ap;
 ****  *  * ****  ***   ****  **  * ** *    *** * || ap=a)
 * ** ****     ****   *  *      ***  *****  ** is a prefix of abcde\n");
  * **  * **  
 *    *  **  ***
   ***  * **     ***   *  * *       *   is not a prefix of abcde");
 * ***  **** *****  * *****  ***  *  ***     **** *      ** * ***  ***    ***  *  ** 0;
* **  *   * ** * * ** *   * *  * *        ** *  *     ** ** **       *  * *
  

Comments

prog.c: In function 'main':
prog.c:6:10: error: 'a' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
          ^
prog.c:6:10: note: each undeclared identifier is reported only once for each function it appears in
prog.c:6:17: error: 'z' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
                 ^
prog.c:10:12: warning: missing terminating " character
     printf("bc is not a prefix of abcde);
            ^
prog.c:10:12: error: missing terminating " character
     printf("bc is not a prefix of abcde);
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.c:11:12: error: expected expression before 'return'
            return 0;
            ^~~~~~
prog.c:12:12: error: expected ';' before '}' token
            }
            ^
prog.c:12:12: error: expected declaration or statement at end of input

---

prog.c: In function 'main':
prog.c:6:10: error: 'a' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
          ^
prog.c:6:10: note: each undeclared identifier is reported only once for each function it appears in
prog.c:6:17: error: 'z' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
                 ^
prog.c:10:12: warning: missing terminating " character
     printf("bc is not a prefix of abcde);
            ^
prog.c:10:12: error: missing terminating " character
     printf("bc is not a prefix of abcde);
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.c:11:12: error: expected expression before 'return'
            return 0;
            ^~~~~~
prog.c:12:12: error: expected ';' before '}' token
            }
            ^
prog.c:12:12: error: expected declaration or statement at end of input

---

prog.c: In function 'main':
prog.c:6:10: error: 'a' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
          ^
prog.c:6:10: note: each undeclared identifier is reported only once for each function it appears in
prog.c:6:17: error: 'z' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
                 ^
prog.c:10:12: warning: missing terminating " character
     printf("bc is not a prefix of abcde);
            ^
prog.c:10:12: error: missing terminating " character
     printf("bc is not a prefix of abcde);
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.c:11:12: error: expected expression before 'return'
            return 0;
            ^~~~~~
prog.c:12:12: error: expected ';' before '}' token
            }
            ^
prog.c:12:12: error: expected declaration or statement at end of input

---

prog.c: In function 'main':
prog.c:6:10: error: 'a' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
          ^
prog.c:6:10: note: each undeclared identifier is reported only once for each function it appears in
prog.c:6:17: error: 'z' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
                 ^
prog.c:10:12: warning: missing terminating " character
     printf("bc is not a prefix of abcde);
            ^
prog.c:10:12: error: missing terminating " character
     printf("bc is not a prefix of abcde);
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.c:11:12: error: expected expression before 'return'
            return 0;
            ^~~~~~
prog.c:12:12: error: expected ';' before '}' token
            }
            ^
prog.c:12:12: error: expected declaration or statement at end of input

---

prog.c: In function 'main':
prog.c:6:10: error: 'a' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
          ^
prog.c:6:10: note: each undeclared identifier is reported only once for each function it appears in
prog.c:6:17: error: 'z' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
                 ^
prog.c:12:12: error: expected declaration or statement at end of input
            }
            ^

---

prog.c: In function 'main':
prog.c:6:10: error: 'a' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
          ^
prog.c:6:10: note: each undeclared identifier is reported only once for each function it appears in
prog.c:6:17: error: 'z' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
                 ^
prog.c:12:12: error: expected declaration or statement at end of input
            }
            ^

---

prog.c: In function 'main':
prog.c:6:10: error: 'a' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
          ^
prog.c:6:10: note: each undeclared identifier is reported only once for each function it appears in
prog.c:6:17: error: 'z' undeclared (first use in this function)
   if(ap>=a&&ap<=z || ap=a)
                 ^
prog.c:12:12: error: expected declaration or statement at end of input
            }
            ^

Answer 3

Hidden content!
 * * * * * * **    * 
*  ****   **** * *   *

char p[1000],s[1000];
int i,pl,sl;

int test(char p[],char s[],int pl, int sl)
{
*   *   *** * ***** *  *    * **  i<pl; i++)
 **  *   **    *** *** ** ** **
* * *********        *   **      *      ***  *   *** *  (p[i]==s[i])
*** * **  ** *  *** * **  ** *** *   * * * ** ***   * 
** *** **  *  *   ** *   * ***  **  *** ***  * *****   *   ***    **  * * *   *   **   * * ***
** * *  *   ** **** ** **** ****     ***   *** **   *   **** *  ***    **** 
 ***    ***  *  * ** **** **** ******    * * *   *  ** **  *   ***   **  **               **   * **    ** 1;
 *   *  ***    * * *  *    * **  * *     **  ** *  * *****  **     **    ******   ** 
** **    *** ** ***** **  * *  **** ** *  *  * ** ** ** *
*  *** ***   * * *   *   *  * *   **  * *         **   *  if(p[i]!=s[i])
* * * *  *    **** **  * * ** * *  *   *     * * *     
**   * *** * **      *   *      ** *   ** * ** * **** *  *****  ** **    * *****  * 0;
   *** ** * **  ******   * * *   ** **   **     **** * ***
**  * **    *******    *
}


int main()
{
*    *       * 
   ***  *** * * 
****  * * **   ",p);
***   *  ** *        * 
* ****   *   * ** *  

sl=strlen(s);
pl=strlen(p);


* **   ****  * && pl<sl)
{

      ****  * *   ** **  *   *    ***   is a prefix of %s",p,s);
}else
{
printf("%s is not a prefix of %s",p,s);
}





}

Comments

Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output

---

Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output

---

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

Answer 4

Hidden content!
#include<stdio.h>
#include<string.h>
int main()
{
   **** * * **  *** *  * * **  **  a[99],b[99];
    int l,i;
 * * *   *  ******  * *  ** ** ********   **** 
   ***      * **   *** * * ******* 
 * **** *** *    ****   ****** * ***
*  **  ***    ***   * * *  **  ** * ** *** 
    {
*  * * *  *  *** *   * * *** ** ** *    * ****  * * *** **    *** 
*****  * *** * **   *** * **    ***  **   **  * *  * 
 *** *  ******* * ** *  ***   * *  *   ** *    ****  ****  * * *   * **** ** * ** * *  ** ** * a prefix of %s",a,b);
   *   * * *      * *     *   *  * * *** ****    * *    * *    *  *   * *** ** ****** *
***** *  *** ** ** **      ** **  ** *** * *********
*  *** *  **  ** ****     ** ** ***   * * *  ***** * ** *
*** *  ***  *** * **   *** **  *********  ***   ** ** 
****  ***  ** ** *  * * ** * ***      *  *  * ** * * * ** * **   *   **  ** ****** * *   **** not a prefix of %s",a,b);
 **  ** *  ****  ***  ****  ***  ****    * *  **** * *  * ** ******  **  ** * **
* *** ** *  *   *        **  * *  **** ***    ** *  *   **
    }


}

Comments

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output

---

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output

---

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output

Answer 5

Hidden content!
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

int prefix(char a[100],char b[100]);


int prefix(char a[100],char b[100])
{
  *   *  ***    * ** * *   *     i;
*     ** **** ** **  ** *** *    count=0;
 * *   * ***  ** ** ****    len;

*  *** *** *** *  **    ******    *  *

**    * *   *  *   ** **    *****   ***** **
*   ** * * * * * **  *   *     
 * *  *  ** ** ** *  ****   *  **  *** ** *  *    * * **
*** *   * **  ***  **  **    **  *** ******  **  **** 
  * * *** *  * ****    ***  * ***   ** ***** * *****  *  ** **       **  *  **    *    *     *** **
* *  ** *  *  * *  *   *   ********   **  ** * *  **  * **
* ****  **     **  * *  ** 


 *  *   **     *** **  ** ******* ** **  *
  ****   * **  * ****** *  *  
 *** * ***  ****      ***  **  ***  **  **   ***    * * ** ***  1;
 * * * * * ** *  *   
 * ** ** ***  *   **   * 

   return 0;
}


int main()
{
*  ***  ** *  *        **  a[100];
 *   ** ** * *   * *** **  **     b[100];


* **   *  *** *   **  **      *** ***  ** * *  ** * *** * **  * *** 
  *   * *  *** **  **  *  **** ** *  * *  **** **  *  ***

  * *  *    * *******  **  * * ***  ****
 **     ***   ** **** * **** ** *** *   *** 

 * * ** * **  ***  **** *    * *   *    

 {
 ****  *    *  * ** ****  ******  * *    ******* ***** * ****      **  is a prefix of %s",a,b);
**  *** * * *   **       
 * **    * ** * * *   * ** * ***  
  *    * *** * * *      ** 
*  * ** ** *   **  ** * ** *  *  *  *     ** * *   *  * **   *  * *  * **  is not a prefix of %s",a,b);
 ** **     * **  *******   *** 


* ** **  **** ** * ** * 0;
}

Comments

prog.c: In function 'main':
prog.c:45:15: warning: format '%[^
   ' expects argument of type 'char *', but argument 2 has type 'char (*)[100]' [-Wformat=]
     scanf("%[^\n]*c%",&a);
               ^
prog.c:45:20: warning: spurious trailing '%' in format [-Wformat=]
     scanf("%[^\n]*c%",&a);
                    ^
prog.c:46:15: warning: format '%[^
   ' expects argument of type 'char *', but argument 2 has type 'char (*)[100]' [-Wformat=]
     scanf("%[^\n]*c%",&b);
               ^
prog.c:46:20: warning: spurious trailing '%' in format [-Wformat=]
     scanf("%[^\n]*c%",&b);
                    ^

---

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output

---

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output

Answer 6

Hidden content!
  *   * ******  ***
* * ***  *     **

int * **
{
  *** ****    **   **  ** * **  *     no idea, I   * * even do it in the * ** *******  * *
    * *  * *      *** ** 0;
}

Comments

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output

Answer 7

Hidden content!
#include ******  ** **
#include  *     ****  *
#include   * **   * * 

int pref(char[],char[]);

int main(){

*    ** *    * * *   * **  * * p[10],s[10];
* **** ** *  **** *  **    *  num;

  *  ***   *  ***    * ***** *   *
** * *    *   *    ***    *  * * *
 **** ***  *  *   ****** *  **** ** *   * *** 
*  *   ** * * * *    *   **  *   **  *** *        **** 

    ***         *   * **  ****  = pref(p,s);

* *   * * ***  * *** * *****
* **  *  *** *   *   ******    ** *    *     ***   * *   * * *** ** *   is a prefix of %s",p,s);
******* ****   * * ** *    * * **
  ** * *   ** *** *  *  *  * *      *      * ***   *  * ** *  **  is not a prefix of %s",p,s);


 return 0;
}

int pref(char p[30],char s[30]){
 ****   ** **    *      *      i;

 **   *  * **   * * * **  ** *  ***** * **  * **
   * * * ***  ***  * * ** ** *    ******  *   *****  ** ****  * **  *  ****  *  ***  *   **        *  ** * **
 * ***  *** ** **   * * * *  **  * ** *   *    ****   **  * * *  *   **    ** *       * * is a prefix of %s",p,s);
**       ** ** *******   **  *  **  **   ** *    *  **** ***
 ****  *   *  **  *** ** **     *****      ***      *   *    **** * *     * ***  *  ***  ** * is not a prefix of %s",p,s);

  *   **  *  * ***    * **

}

Comments

prog.c: In function 'main':
prog.c:12:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     gets(p);
     ^~~~
In file included from prog.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
prog.c:13:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     gets(s);
     ^~~~
In file included from prog.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/tmp/cc0tBG5r.o: In function `main':
prog.c:(.text+0x1f): warning: the `gets' function is dangerous and should not be used.

---

prog.c: In function 'main':
prog.c:10:13: error: stray '#' in program
     int num;#include <stdio.h>
             ^
prog.c:10:14: error: 'include' undeclared (first use in this function)
     int num;#include <stdio.h>
              ^~~~~~~
prog.c:10:14: note: each undeclared identifier is reported only once for each function it appears in
prog.c:10:23: error: 'stdio' undeclared (first use in this function)
     int num;#include <stdio.h>
                       ^~~~~
prog.c:14:1: error: expected expression before 'int'
 int pref(char[],char[]);
 ^~~
prog.c: In function 'main':
prog.c:23:13: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[10]' [-Wformat=]
     scanf("%s",&p);
             ^
prog.c:24:13: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[10]' [-Wformat=]
     scanf("%s",&s);
             ^
prog.c: In function 'main':
prog.c:51:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     gets(p);
     ^~~~
In file included from prog.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
prog.c:52:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     gets(s);
     ^~~~
In file included from prog.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~

---

prog.c: In function 'main':
prog.c:14:13: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[10]' [-Wformat=]
     scanf("%s",&p);
             ^
prog.c:15:13: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[10]' [-Wformat=]
     scanf("%s",&s);
             ^

Answer 8

Hidden content!
   *  **   *   **** 
 *       ***     *   **  

int main()
{
**    * **    length1,  **** c;
* *    **  a[100];
**  * **  * b[100];
 *   * **     d[100];

 *** * *      *  ***  
*  *  *   * **  *  ****   ** *    * **

   *    ***  *** *

* *  *   ***  ** *  * *

* ****   * ***  * ** 
* * **
  *  * **  ** * *    * *  is a prefix of  **   * * *  
**** *
 ***      *  ** 
  * * *
**  *** *    * *   is not a prefix of *    **** *  
** *     *

}

Comments

prog.c: In function 'main':
prog.c:11:10: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[100]' [-Wformat=]
  scanf("%s",&a);
          ^
prog.c:12:10: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[100]' [-Wformat=]
  scanf("%s",&b);
          ^
prog.c:24:11: warning: format '%s' expects a matching 'char *' argument [-Wformat=]
  printf("%s is not a prefix of %s,a,b");
           ^
prog.c:24:33: warning: format '%s' expects a matching 'char *' argument [-Wformat=]
  printf("%s is not a prefix of %s,a,b");
                                 ^

Answer 9

Hidden content!
   ***      **** **  
 **  *   ****  *   

int main()
{
** **** * ******    *     str;
** *******  *   ** ** *** * ***** i, p, s;

**  * * *****   * ** ** *     *  *   ****     *  &p, &s);

  *  *** ***  *  * * * **    (i<=0; &p; i++);
   *     *  * *  ******* * ***** *
 * *  ****** ***** **  ** * ***** *   * ***    ** * &p);
 *     * ** *** * **** * * * ********  * ** ***    *  *  
 ** **   ** ** * * ** ** * **
**  ****    *** *    *  

*   *  ***         **   *  *  * 0;
}

Comments

prog.c: In function 'main':
prog.c:12:7: error: expected '(' before '{' token
     if{}
       ^
prog.c:13:12: warning: too many arguments for format [-Wformat-extra-args]
     printf("abc", &p);
            ^~~~~
prog.c:14:13: warning: format '%d' expects a matching 'int *' argument [-Wformat=]
     scanf("%d");
             ^

Answer 10

Hidden content!
*    **    ** *   **
**  **   **  * * * *  
int main (){
char  * **   
char * ** **
 **       *** ** ****  *  *
* * ****  **    ** * ***** ***
*   * *** *   * **  * *   * * * *
**   **  *** *    * ** ***      * 
** * * **  ** **
**** ****       is a prefix of *   ** *  * *    **  **
}
else{
  ****   * * is not a prefix of %s *****   *******  **
}
    *  0;
}

Comments

prog.c: In function 'main':
prog.c:7:9: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[100]' [-Wformat=]
 scanf("%s",&string1);
         ^
prog.c:9:9: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[100]' [-Wformat=]
 scanf("%s",&string2);
         ^