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);
         ^