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);
         ^