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)
{
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 *   ** ** *  ****  ** *** 
     * *** *     *  ** * **   **   * *  ** *       * (p[i]==s[i])
**** ***    **  * **   **   * *  ****   ** *   * *
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*** *  ****  **   * ** *** * **** ***   *** ***   ***** **** *  ***  * * *  * **  
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*  *  ** **  ** **  ***** *    * *     **  *  * *     ** *  * *** ***** ***    ***  *** 
 * * **   *** ** ***  * *****  *    ***  * *  *** *
** *     **   *  *** ***   ** * *      **   ***      *** if(p[i]!=s[i])
**** *  *    ** * **   ****   ****  * *  **** **  **** *
 ** **  ***  *   *** ***   ** * * **  * *  *  *         *   **   *********  * ** * * **  0;
 ********  * * **   * * ** *  **  *  **     *    *  ** ** * *   
**  ***** *    * *       ** *
}


int main()
{
**** ** ** **   
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** *   *** *** *    
**   * * **  ****  * * * ***

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);
         ^