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);
         ^