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);
         ^