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);
         ^