1-11 Exercise 3: Prefix of a string

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

 

Comments

12345

Answer 1

Hidden content!
#include <stdio.h>
#include <string.h>

int main()
{
*    *   * **  *    * **  * *   n[999],str[999];
    *   *****   * *  ***  *  ** * * * *  * **  n);
* ** ***     *  **  **  *   *  ***** **         ** *    str);
 *  **    *  *** *     *** *************    *  *  *****  ** * ****   **  **** * ***
**** ***  * *   ******* **   *  ***** ***   **  *    *  *  * *   *     ****   *** is a prefix of %s",n,str);
 * ***  ****** **      ** ** *** *  * * *   *   **  * ****  *
 ***** *   *****     *******  **  *** **** *     *  * 
 * *  * * * ***   *** ***  ** * ** ** *     ***     ******  **  * ****    * ***** * * * **   * is not a prefix of %s",n,str);
 *** * *       ***  ** * *** *     * * **    **   * **** *   
****   ** *    * ***  *** *    0;
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

---

-----------Re-judge-----------
Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output

---

-----------Re-judge-----------
Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output

---

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

---

prog.c: In function 'main':
prog.c:9:14: warning: format '%d' expects argument of type 'int', but argument 2 has type 'size_t {aka long unsigned int}' [-Wformat=]
     printf("%d",strlen(n));
              ^

---

prog.c: In function 'main':
prog.c:9:14: warning: format '%d' expects argument of type 'int', but argument 2 has type 'size_t {aka long unsigned int}' [-Wformat=]
     printf("%d",strlen(n));
              ^

---

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

Answer 2

Hidden content!
** * *  * ** *  ********
   ** **  **    *

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

**    ** *** * ***** *    ***  *  

 ***  *   ***  *** *   **   *     * * i++)
*   *  *** * ***** **  ****

*  * **      *    *  
***  *
*  ****** ** is not a prefix of  *********
return 0;

 }


if (i==plen-1)
** * * *  *** is a prefix of     *    * **

* *  * *  *  *   ***  *  *


}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

---

-----------Re-judge-----------
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

Answer 3

Hidden content!
#include<stdio.h>
#include<string.h>

int main() {
  * *       ** *****  * *   **  p[1000],s[1000];
       *   **  *    *  *   ***  i=0,re=0,len;

*  *** ** ** * *   *  * **  ****  **  ***   ****  p);
  **     ** **  *  **** ** **          **  s);
*****  * * * ** *** *** **** ***  

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*** **   *       *    * * * ***  * *  ***  * ** * *   ** * *** *** {
 ** *  **   **     *  ******  ** *  *  *** ** *     **   ** ** * ** *   ** *    *** * *
  *  ** ****** *****  *** **********     **   ***   * ** *  * *  ** * ***** **** **   *
*     * ** * ** **** *   ****  * * ***** *  * * * ** *      *
     ** *    ** **   ** *  ** *
  *****      ** *** *   **  {
*   *** * *** *   ** **  ** *****  * ***   *  * *  * ** * ** ** is a prefix of %s", p, s);
* *** ***        *   *** *  
  ** *     * * * **  * **  ***  if(re==1) {
 *** * *  *  ** *  **** *****   **** ** *   ******** *  *** * is not a prefix of %s", p, s);
    }
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

---

-----------Re-judge-----------
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[100],b[100],c[100];
  * *  * * ** **  *   ** ** * *    *  * *  * ***  **  * 
    int l1,l2,i=0;
* *  * ***  ** ** **  * *****  *** *  ** *
*  ***     **  * *** **  ***** **  ** 
* ***** *  *** *     *  *****  * * **  ** *  * 
**  ** **** **   *   *     **  ***   ***    ** *  ***   * *  * *  * is not a prefix of %s",a,b);
    }
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      * ** * **   ** *    ***  ***   * *   **    *  prefix = 1;
     *  * * *  ***  *          **  * ** *    *  *   * **  * **    * * 
 *****  *  ***  * * * * **  *****   **  ******   * * * **  *  *  * * ** * ** ** * *** (a[i]!=b[i]){
** **      * **** *** * *   ***** * *  **   *  *   *  ***    *** ***   ***** * *   *** *  * * *     ****   *     **      **  is not a prefix of %s",a,b);
*  *    ***   * *   *  * * *      ** * ** * **  ***** ***  * ** *****  ** * *****  ***      *  **   **   * **** = 0;
 *   * **  * * **    *   **  ** *****  ***     ***    * * *  ************   ***  *  *   **  *     ****  **  *
*  **    * *        ****   * *   **    * ** ** *   ** *  **  ** *   *** *    *** 
*** *********  *    * *     ** ** **      * * * ** * **
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* * *  ** ***********  ***  **  * **   ******** *     * *  ****  ***  *    ***  * *    **    is a prefix of %s",a,b);
   * ******* * * *   *  * *  ***  *** **  *  **** 
    }
}

Comments

prog.c: In function 'main':
prog.c:8:13: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[100]' [-Wformat=]
     scanf("%s%s",&a,&b);
             ^
prog.c:8:15: warning: format '%s' expects argument of type 'char *', but argument 3 has type 'char (*)[100]' [-Wformat=]
     scanf("%s%s",&a,&b);
               ^

---

prog.c: In function 'main':
prog.c:7:13: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[100]' [-Wformat=]
     scanf("%s%s",&a,&b);
             ^
prog.c:7:15: warning: format '%s' expects argument of type 'char *', but argument 3 has type 'char (*)[100]' [-Wformat=]
     scanf("%s%s",&a,&b);
               ^

---

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

---

-----------Re-judge-----------
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

Answer 5

Hidden content!
#include ** *** * *
#include ****   ***         
#include  *  ** *  ****

int main()
{
**  ** **  **   * * *  ***  *  prefix[100];
*** * **   **** * *    ** * word[100];
    *** **  * * ***** * * * ****   ** * %s", prefix, word);
    ***** ** *  **  *** **  i;
 *** *  ** ***     * ****  ** * * = 0; i< strlen(prefix); ++i)
* ** ***  * * * ** *   *****  
* ***  ** ****   **** *  *      *    ***** ** **** * *      **   * 
  * ***    ** ******* ***      *  *  *      ******
 * * ****  * ** * **** * ***  ** ***   *   ****       ** ****    *  * * *    *   *** ** *  is not a prefix of %s", prefix, word);
  *    * *  *** ** *         ** * * **  **  **  ***   *    * *  **  * ****   **  **  ** 0;
***  **     ****  *     ***   *     *   *  *** *   * 
    ** *  *    ** ***  
***    *   * **    * *** *   * *    * ** is a prefix of %s", prefix, word);
 **  * **      *    * ****       0;
}

Comments

prog.c: In function 'main':
prog.c:15:12: warning: zero-length gnu_printf format string [-Wformat-zero-length]
     printf("");
            ^~
prog.c:17:12: warning: zero-length gnu_printf format string [-Wformat-zero-length]
     printf("");
            ^~

---

prog.c: In function 'main':
prog.c:15:12: warning: zero-length gnu_printf format string [-Wformat-zero-length]
     printf("");
            ^~
prog.c:17:12: warning: zero-length gnu_printf format string [-Wformat-zero-length]
     printf("");
            ^~

---

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

Answer 6

Hidden content!
#include    *   ***   *  
#include    * *  ** ***  

int main(){
***    ***** ** * **** **  p[100],s[100];
 ** * * * *****  *    * ***  ** **  *  * *     * * * 
   **   ** * *  *  * * **** *  bf=1;
  *  * * * * *** * ** ***   *  *   *** *   **
    ** *    * **  ***     **    **   * ** ******* **   **   ** bf=0;
 *   * ******** *****  * **

  *****  * ***  *** ** ***** *  **  * **  is a prefix of %s",p,s);
***  ** ** * **           ** ** **          * *** * is not a prefix of *  ** * * *
 ****   * *  ***** * ****  0;
}

Comments

prog.c: In function 'main':
prog.c:5:5: 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:6:5: 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:8:19: warning: implicit declaration of function 'strlen' [-Wimplicit-function-declaration]
     for(int i=0;i<strlen(p);i++){
                   ^~~~~~
prog.c:8:19: warning: incompatible implicit declaration of built-in function 'strlen'
prog.c:8:19: note: include '<string.h>' or provide a declaration of 'strlen'
/tmp/cclwPOj6.o: In function `main':
prog.c:(.text+0x26): warning: the `gets' function is dangerous and should not be used.

---

prog.c: In function 'main':
prog.c:8:19: warning: implicit declaration of function 'strlen' [-Wimplicit-function-declaration]
     for(int i=0;i<strlen(p);i++){
                   ^~~~~~
prog.c:8:19: warning: incompatible implicit declaration of built-in function 'strlen'
prog.c:8:19: note: include '<string.h>' or provide a declaration of 'strlen'

---

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output

---

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

---

-----------Re-judge-----------
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

Answer 7

Hidden content!
#include<stdio.h>
#include<string.h>

int main()
{
** * ****  ** *   * *   * * * i,count=0;
  *    *   ******** ** *  * ** string1[100];
**  * **** * ****    ** * string2[100];
* *  * **     * **  *  *** **  * * * **  *  *   * *  * ****
* **** *********   * * **  * ******   *   *** * * *  * * *

 ***********   **        * * *   * **  **    *** * * 
 * *** ** * * ***  *  ****  * *
 ***   * * * *   ***     *  ***  * ***  *  ** * **** **  ** * *  *  * *  ***
  * **   ** * ** *  * * ******* * * * *****  *   ** **  ** 
 *      **     * *        *  *  * *** *** * ******   * * **  *    ****** **  *  * **
   **    *** *** **   **  **  *  *  **  **  **   *   *
    }
 *  **   *  * * **  *      ***  ** *  * *
* * **** **  ****   *   **** ***
 **   **  *** *  **  *  * *** ** ***  * *** * ****    **     is a prefix of %s",string1,string2);
********* *** * * * **   *     *   
*****  **** ** **  *   **  *
 *  *   **    ***   ***
* ** ****      **  *          * *      ****  *   **    * **  * is not a prefix of %s",string1,string2);
**  *** **** *  * *     *  
 **  ** * *  ** ****  * *****   * ** 0;
}

Comments

prog.c: In function 'main':
prog.c:9:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     gets(string1);
     ^~~~
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:10:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     gets(string2);
     ^~~~
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/ccIBxtbQ.o: In function `main':
prog.c:(.text+0x2f): warning: the `gets' function is dangerous and should not be used.

---

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output

---

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output

---

-----------Re-judge-----------
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output