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()
{
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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