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);
         ^