Learn to Program with C_ Learn to Program using the Popular C Programming Language ( PDFDrive )

Chapter 8 ■ Arrays
void reverse(char str[]) {
void swap(char [], int, int);
int lo, hi;
for (lo = 0, hi = strlen(str) - 1; lo < hi; lo++, hi--)
swap(str, lo, hi);
} //end reverse
void swap(char str[], int i, int j) {
char c = str[i];
str[i] = str[j];
str[j] = c;
} //end swap
The following is a sample run of P8.3:
Type some data and I will reverse it
Once upon a time
emit a nopu ecnO
Reversing a string may not seem too important in its own right, but there are times when we
need to reverse the elements of an array. For example, we may have a list of student marks stored
in an array and sorted in ascending order, like this:
If we want the marks in descending order, all we have to do is reverse the array, like this:
8.9 Palindrome
Consider the problem of determining if a given string is a palindrome (the same when spelt
forwards or backwards). Examples of palindromes (ignoring case, punctuation and spaces) are:
civic
Race car
Madam, I'm Adam.
A man, a plan, a canal, Panama.
220
www.it-ebooks.info