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!
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* **  * * *   **   

int main()
{
****       *   *  * **** i,plen;
  **  *  *  *  *     * *     *    * 
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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);
 *** ** ** *    *** *****   * *  ** *  ** *

 * *** **  * ** *   **  ***  ****  * *   {
    **** ******   *  * *** **** ****  ***  ** * **     {
***** * *  ******   * **        *    ** ****  *  *  *   ** ****   *  *   *   ***  * * *
*     ***   *  ** *  * ***      **  *  * *  * ***  ** * **** *** * ***  *   * *
 ****  * ** *   *  *     * **** *    * ** ** **   *  *
*** *** *  * **   * ** **
*   *      ** * ***   *    * *** {
***     * **     *     *  **    *  ** *      * ***********   **   *** 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);
    }
  ****    **** **  *      ** if(l1<=l2){
* *    * ***  ** *  *  *** * * *** *        **** * **    *   prefix = 1;
      *  ** ** *  ***    * *    * * *  *** *   * **   *  ***  **** * ***** 
*  **  ***** **  * *** ****  *       *  * ****    *** ** * ** * ** * **    *    **  ** (a[i]!=b[i]){
 * *  ** *****  ** *   *  * *  ***** ** *  *  **** ****  *** * * *  * * * ***   *  ** * ** ***  ** * * ***   ***  *    * * ***  **  is not a prefix of %s",a,b);
*******  *  ******    ****  ** * ****  *****      * ***  * *   *  ** *** *** *  ** *  ***   *  * *  ****   = 0;
   ** * * * ** *   ** *   **  ***   ** *  *  **    *  * ** **  *    * *             *   * *     **     ****  *** * ** 
 *  **  *   ** * **  * *   ** **  ***     *** *   **   *  **  * ** * *  *   **  ** ***
  *   ***  *** * * **** * **   **  * **  *****   * ** *  
        * *   * * ** **     ***   * ***   *  *      * *** * * == 1){
** *   ** *** *     ************* *  *****  *   **   *** * *  ** *** * ** *****   **** *** 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