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