wordshift.cpp

#include <iostream>
#include <string>
#include <cstring>
#include <stdlib.h>
#include <string.h>
using namespace std;


void shiftR (char sentence[], int shift, int length);
void shiftL (char sentence[], int shift, int length);
void reverse (char sentence[], int length);
void swap (char sentence[], int a, int b);


int main ()
{
    const int LENGTH = 50;
    char sentence[LENGTH];
    int length;
    string menu;
    int shift;

    cout << "Please enter the string you wish to manipulate.\n";
    cin.getline(sentence, LENGTH);
    length = strlen(sentence);

    cout << "\n\n\nWhat manipulation would you like to perform on your string?" << endl;
    cout << "You have 4 choices:\n";
    cout << "\"R(x)\" will shift all characters in the string (x) positions right.\n";
    cout << "\"L(x)\" will shift all characters in the string (x) positions left.\n";
    cout << "\"rev\" will reverse the string.\n";
    cout << "\"quit\" will end the program.\n";

    do
    {

        cout << "Please enter a command: ";
        cin >> menu;

        if(menu.at(0) == 'L')
        {
            shift = atoi((menu.substr(1, string::npos).c_str()));
            shiftL(sentence, shift, length);
        }

        else if(menu.at(0) == 'R')
        {
            shift = atoi((menu.substr(1, string::npos).c_str()));
            shiftR(sentence, shift, length);
        }

        else if((menu.at(0) == 'r') && (menu.at(1) == 'e') && (menu.at(2) == 'v'))

            reverse(sentence, length);

        else if((menu.at(0) == 'q') && (menu.at(1) == 'u') && (menu.at(2) == 'i') && (menu.at(3) == 't'))

            return 0;

        else

            cout << "ERROR: Please enter the menu selection as indicated exactly.\n";

    }while(1);

    return 0;
}


void shiftR (char sentence[], int shift,int length)
{


    for(int j = 0; j < shift; j++)
    {
        char last = sentence[length -1];

        for(int i = (length-1); i >= 1; i--)
        {
            sentence[i] = sentence[i - 1];
        }

        sentence[0] = last;
    }


    cout << sentence << endl;
}

void shiftL (char sentence[], int shift, int length)
{

    for(int j = 0; j < shift; j++)
    {
        char first = sentence[0];

        for(int i = 0; i < length-1; i++)
        {
            sentence[i] = sentence[i + 1];
        }

        sentence[length-1] = first;
    }

    cout << sentence << endl;
}

void reverse (char sentence[], int length)
{
    int a, b;

    for(a = 0; a < (length/2); a++)
    {
        b = length - a - 1;
        swap(sentence, a, b);
    }

    cout << sentence << endl;
}

void swap(char sentence[], int a, int b)
{
    char temporary = sentence[a];

    sentence[a] = sentence[b];
    sentence[b] = temporary;
}