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