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);
         ^