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