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;
    **  *** **  **** ** *        ** 
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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