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);
         ^