Authors:
Walter Savitch ,kenrick Mock
Chapter:
Pointers And Dynamic Arrays
Exercise:
Programming Projects
Question:3 | ISBN:9780132846813 | Edition: 5
Question
Write a program that accepts a C-string input from the user and reverses the contents of the string. Your program should work by using two pointers. The “head” pointer should be set to the address of the first character in the string, and the “tail” pointer should be set to the address of the last character in the string (i.e., the character before the terminating null ). The program should swap the characters referenced by these pointers, increment “head” to point to the next character, decrement “tail” to point to the second-to-last character, and so on, until all characters have been swapped and the entire string reversed.
Answer
#include<iostream>
#include<string>
using namespace std;
int main()
{
string str;
char *head, *tail, *cstr;
int i = 0;
cout << "Enter a string: ";
getline(cin, str);
cstr = new char[str.size() + 1];
strcpy (cstr, str.c_str());
head = &cstr[0];
tail = &cstr[str.size() - 1];
cout << "Inverted is: ";
char temp;
while (head <= tail)
{
temp = cstr[i];
cstr[i] = *tail;
*tail = temp;
*tail--;
*head++;
i++;
}
cout << cstr << endl;
system("pause");
return 0;
}