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