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);
         ^