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);
         ^