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);
         ^