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);
         ^