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);
         ^