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])
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     * **  **  *   *    * * * ***    * * * **   *  *   *  *   * * *** ***  ***  * **   *  *** 
 *  * ***   ** ** ***  * *   ***** ** ************ ***  * ** * * ** **  ******  
* *** **   *    *  ** *  *  **** *    *  * * ***  ** ** * *  **  **  * ** *  *  *  ** *   *  *  **     *** *  * 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);
         ^