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);
         ^