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)
{
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 *   *   * **   **   *  * **
   *   *   **    **  *   **    ** ** ****   *      *  * ** (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);
         ^