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);
         ^