String Sequence Analyzer - c

Question

First need to convert the string into its individual ASCII value and then we have to accomplish following task:
Check if two consecutive ASCII(values of the string) difference is 1 or not. If difference is 1
then they will be coupled together and print them.
ex.
ABCD
individual ASCII value : 65 67 68 69
Difference of two consecutive ASCII value is 1 so coupled together then print them.
#include<stdio.h>
#include<string.h>
int main(){
char str[100];
int i=0;
printf("Enter any string: ");
scanf("%s",str);
printf("ASCII values of each characters of given string: ");
while(str[i])
printf("%d ",str[i++]);
return 0;
}
This code print the ASCII values but i don't know how to check the difference between two consecutive values and how to couple them.

Answer 1

#include<stdio.h>
int main(){
char str[100]="";
int i, last;
printf("Enter any string: ");
scanf("%s",str+1);//top is dummy
printf("ASCII values of each characters of given string: ");
i = 1;
while(str[i])
printf("%d ",str[i++]);
printf("\n");
last = i;
for(i=1;i<last;++i){
if(str[i] == str[i-1] + 1 || str[i] == str[i-1] - 1 ||
str[i] == str[i+1] + 1 || str[i] == str[i+1] - 1)
printf("%c", str[i]);
}
printf("\n");
return 0;
}

Answer 2

Well to give you a clue and not solve your problem entierly:
As char is an integral type in C, do the following:
if( 'B' - 'A' == 1){
printf("OK\n");
}
if( 'C' - 'A' == 2){
printf("OK\n");
} //etc
(On ideone)
Just think about what should you change in the loop and I think you'll get the idea :)

Answer 3

I think the easiest way to go about your problem it after you read string, create a pointer to it, then just advance a pointer through string checking where *pointer - *(pointer - 1) == 1. Do this for pointer values > string[0] and you can check if your two adjacent characters are coupled. (you will need the absolute value of the difference). A quick hack at your solution would look something like this:
#include<stdio.h>
#include<string.h>
int absdiff (unsigned a, unsigned b) {
if (a == b) return 0;
return (a > b) ? a - b : b -a;
}
int main(){
char str[100];
char cpl[3];
cpl[2]='\0'; // null terminate cpl
//int i=0;
printf("Enter any string: ");
scanf("%s",str);
printf("ASCII values of each characters of given string: \n");
char *ptr = str;
while(*ptr) {
if ((ptr - str) > 0) {
if (absdiff (*ptr, *(ptr - 1)) == 1) {
cpl[0] = *(ptr - 1);
cpl[1] = *ptr;
printf (" coupled : %s\n", cpl);
ptr++;
continue;
}
}
printf(" %c = %u\n",*ptr, *ptr);
ptr++;
}
putchar ('\n');
return 0;
}
And if given the string 'my_dog_is_unable_to_bark.' would produce the following output:
Enter any string: my_dog_is_unable_to_bark.
ASCII values of each characters of given string:
m = 109
y = 121
_ = 95
d = 100
o = 111
g = 103
_ = 95
i = 105
s = 115
_ = 95
u = 117
n = 110
a = 97
coupled : ab
l = 108
e = 101
_ = 95
t = 116
o = 111
_ = 95
b = 98
coupled : ba
r = 114
k = 107
. = 46
Of course you can reformat the output in any manner you like, but for illustrative purposes, this gave a good confirmation of the character -> unsigned int values.