From 465acba1fc8241f8ab79aecf99df5252198ba60d Mon Sep 17 00:00:00 2001
From: Chris <skippychris10@gmail.com>
Date: Thu, 11 Feb 2016 22:10:58 -0400
Subject: [PATCH] Create itw.cpp

The purpose of this C++11 program is to convert an integer into its corresponding word(s).
---
 itw.cpp | 93 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 itw.cpp

diff --git a/itw.cpp b/itw.cpp
new file mode 100644
index 0000000..9ad9a36
--- /dev/null
+++ b/itw.cpp
@@ -0,0 +1,93 @@
+#include <iostream>   //Used for obvious reasons
+#include <string>    //Used for manipulating strings
+#include <cmath>    //Used for absolute value function.
+#include <regex>   //Used for sanitizing input
+
+using namespace std; //Used for obvious reasons, this a simple program, no real ambiguity.
+
+string int_to_word(int n)
+{
+    string result     = "";                 //Initialization for the variable in which the result will be stored
+    string nstring    = to_string(abs(n)); //Variable that stores the positive string representation of number.
+    int nstringlen    = nstring.length(); //Variable that stores the length of the number (in this case, string format)
+
+    if (n <  0) {   result += "minus "; n = abs(n);    } //Check if input is negative, if so, add minus word to string and make num positive.
+
+    const string ones[] = //String array for teens (2 digit numbers) and kids (1 digit numbers).
+    {
+    "",        "one",     "two",       "three",    "four",
+    "five",    "six",     "seven",     "eight",    "nine",
+    "ten",     "eleven",  "twelve",    "thirteen", "fourteen",
+    "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"
+    };
+
+    const string tens[] = //String array for double digits that are multiples of 10.
+    {
+    "",        "twenty",    "thirty",   "fourty",   "fifty",   
+    "sixty",   "seventy",   "eighty",   "ninety"
+    };
+    
+    const string powers[] = //String array for powers.
+    {
+    "", "hundred", "thousand", "million"
+    };
+
+    //Processing begins here, in all cases, it goes through each character(s) of string and fetches match in the string array.
+    if (n < 20)
+    {
+        result += ones[n];
+    }else 
+    if (nstringlen < 3) //Less than 3 digits (10's)
+    {
+        result += tens[(nstring[0]) - '0'-1] + " " + ones[(nstring[1]) - '0']; 
+    }else
+    if (nstringlen < 4) //Less than 4 digits (100's)
+    {
+        result += ones[(nstring[0]) - '0'] + " " + powers[1] + " " + int_to_word(stoi(nstring.substr(1,2))); //mmm some tasty recursion
+    }else
+    if (nstringlen < 5) //Less than 5 digits (1000's)
+    {
+        result += ones[(nstring[0]) - '0'] + " " + powers[2] + " " + int_to_word(stoi(nstring.substr(1,3))); //mmm some more tasty recursion!
+    }else
+    if (nstringlen < 6) //Less than 6 digits (10k's)
+    {
+        result += int_to_word(stoi(nstring.substr(0,2))) + " " + powers[2] + " " + int_to_word(stoi(nstring.substr(2,5))); //Newsflash, it's not gonna stop with recursion.
+    }else
+    if (nstringlen < 7) //Less than 7 digits (100k's)
+    {
+        result += int_to_word(stoi(nstring.substr(0,3))) + " " + powers[2] + " " + int_to_word(stoi(nstring.substr(3,6))); //Okay...
+    }else
+    if (nstringlen < 8) //Less than 8 digits (1m's)
+    {
+        result += ones[(nstring[0]) - '0'] + " " + powers[3] + " " + int_to_word(stoi(nstring.substr(1,7))); //A little bit less recursion
+    }else
+    if (nstringlen < 9) //Less than 9 digits (10m's)
+    {
+        result += int_to_word(stoi(nstring.substr(0,2))) + " " + powers[3] + " " + int_to_word(stoi(nstring.substr(2,8))); //More recursion again!
+    }else
+    if (nstringlen < 10) //Less than 10 digits (100m's)
+    {
+        result += int_to_word(stoi(nstring.substr(0,3))) + " " + powers[3] + " " + int_to_word(stoi(nstring.substr(3,8))); //Done with recursion!
+    }else{ //Over 100m's
+        result += "\nI'm afraid you have exceeded the programs capacity.";
+    }
+
+    return result;
+}
+
+int main() 
+{
+    string num = ""; //Variable Initialization
+    cout << "Welcome to the interger to word converter!" << endl; 
+    label: cout << "Please enter a number ranging from -999,999,999 to 999,999,999 : " << endl;
+    getline(cin, num); //Input Capture
+    if (regex_match(num, regex("\\-?[0-9]{1,9}"))) //You need some regex to filter out the dirty input.
+    {
+        if (num != "0" && num != "-0"){ cout << int_to_word(stoi(num)) << endl; }else{ cout << "zero" << endl;}
+    }else{
+        cout << "Make sure you input a number lower in the specified range." << endl;
+        goto label; //Jumping around the code. Some clever stuff I learnt in Theory of Computation Class (little late, I know).
+    }
+
+    return 0;
+}