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);
         ^