7-14

#include<stdio.h>

int main(void)

{

         int i,k;

         char str1[80],str2[80];

         long number;

         printf("Enter a string:");

         i=0;

         while((str1[i]=getchar())!='\n')

                   i++;

         str1[i]='\0';

         k=0;

         for(i=0;str1[i]!='\0';i++)

                   if

                            (str1[i]>='0'&&str1[i]<='9'||str1[i]>='a'&&str1[i]<='f'||str1[i]>='A'&&str1[i]<='F')

                   {

                            str2[k]=str1[i];

                            k++;

                   }

                   str2[k]='\0';

                   number=0;

                   for(i=0;str2[i]!='\0';i++)

                            if(str2[i]>='0'&&str2[i]<='9')

                                     number=number*16+str2[i]-'0';

                            else if(str2[i]>='a'&&str2[i]<='f')

                                     number=number*16+str2[i]-'a'+10;

                            else if(str2[i]>='A'&&str2[i]<='F')

                                     number=number*16+str2[i]-'A'+10;

                            printf("New string:");

                            for(i=0;str2[i]!='\0';i++)

                                     putchar(str2[i]);

                            printf("\n");

                            printf("number=%ld\n",number);

 

                            return 0;

}