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

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

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