Program to convert a given number to words (original) (raw)
Last Updated : 12 Nov, 2024
Given a non-negative integer n, the task is to convert the given number into its English representation according to International Number System.
**Examples:
**Input: n = 0
**Output: "Zero"**Input: n = 123
****Output: "**One Hundred Twenty Three"**Input: n = 10245
Output: "Ten Thousand Two Hundred Forty Five"**Input: n = 2147483647
**Output: "Two Billion One Hundred Forty Seven Million Four Hundred Eighty Three Thousand Six Hundred Forty Seven"
Table of Content
- [Approach 1] By breaking down the number into groups of three digits
- [Approach 2] By Mapping Key Numeric Values with English Words
[Approach 1] By breaking down the number into groups of three digits
The idea is to divide the number into **groups of three digits (Thousands, Millions, Billions) and process each group separately. For each group, we convert the digits in the **Hundreds, **Tens, and **Units places into their corresponding words, then, append the corresponding **multiplier (like Thousand, Million, Billion). This process continues until the entire number is traversed. Finally, we combine all the groups, which form the complete English representation of the given number.
C++ `
// C++ program to convert number into words by breaking // it into groups of three
#include #include #include using namespace std;
string convertToWords(int n) { if (n == 0) return "Zero";
// Words for numbers 0 to 19
vector<string> units = {
"", "One", "Two", "Three",
"Four", "Five", "Six", "Seven",
"Eight", "Nine", "Ten", "Eleven",
"Twelve", "Thirteen", "Fourteen", "Fifteen",
"Sixteen", "Seventeen", "Eighteen", "Nineteen"
};
// Words for numbers multiple of 10
vector<string> tens = {
"", "", "Twenty", "Thirty", "Forty",
"Fifty", "Sixty", "Seventy", "Eighty", "Ninety"
};
vector<string> multiplier =
{"", "Thousand", "Million", "Billion"};
string res = "";
int group = 0;
// Process number in group of 1000s
while (n > 0) {
if (n % 1000 != 0) {
int value = n % 1000;
string temp = "";
// Handle 3 digit number
if (value >= 100) {
temp = units[value / 100] + " Hundred ";
value %= 100;
}
// Handle 2 digit number
if (value >= 20) {
temp += tens[value / 10] + " ";
value %= 10;
}
// Handle unit number
if (value > 0) {
temp += units[value] + " ";
}
// Add the multiplier according to the group
temp += multiplier[group] + " ";
// Add this group result to overall result
res = temp + res;
}
n /= 1000;
group++;
}
// Remove trailing space
return res.substr(0, res.find_last_not_of(" ") + 1);}
int main() { int n = 2147483647; cout << convertToWords(n) << endl; return 0; }
Java
// Java program to convert number into words by breaking // it into groups of three
import java.util.*;
class GfG { static String convertToWords(int n) { if (n == 0) return "Zero";
// Words for numbers 0 to 19
String[] units = {
"", "One", "Two", "Three",
"Four", "Five", "Six", "Seven",
"Eight", "Nine", "Ten", "Eleven",
"Twelve", "Thirteen", "Fourteen", "Fifteen",
"Sixteen", "Seventeen", "Eighteen", "Nineteen"
};
// Words for numbers multiple of 10
String[] tens = {
"", "", "Twenty", "Thirty", "Forty",
"Fifty", "Sixty", "Seventy", "Eighty", "Ninety"
};
String[] multiplier =
{"", "Thousand", "Million", "Billion"};
String res = "";
int group = 0;
// Process number in group of 1000s
while (n > 0) {
if (n % 1000 != 0) {
int value = n % 1000;
String temp = "";
// Handle 3 digit number
if (value >= 100) {
temp = units[value / 100] + " Hundred ";
value %= 100;
}
// Handle 2 digit number
if (value >= 20) {
temp += tens[value / 10] + " ";
value %= 10;
}
// Handle unit number
if (value > 0) {
temp += units[value] + " ";
}
// Add the multiplier according to the group
temp += multiplier[group] + " ";
// Add this group result to overall result
res = temp + res;
}
n /= 1000;
group++;
}
// Remove trailing space
return res.trim();
}
public static void main(String[] args) {
int n = 2147483647;
System.out.println(convertToWords(n));
}}
Python
Python program to convert number into words by breaking
it into groups of three
def convertToWords(n): if n == 0: return "Zero"
# Words for numbers 0 to 19
units = [
"", "One", "Two", "Three",
"Four", "Five", "Six", "Seven",
"Eight", "Nine", "Ten", "Eleven",
"Twelve", "Thirteen", "Fourteen", "Fifteen",
"Sixteen", "Seventeen", "Eighteen", "Nineteen"
]
# Words for numbers multiple of 10
tens = [
"", "", "Twenty", "Thirty", "Forty",
"Fifty", "Sixty", "Seventy", "Eighty", "Ninety"
]
multiplier = ["", "Thousand", "Million", "Billion"]
res = ""
group = 0
# Process number in group of 1000s
while n > 0:
if n % 1000 != 0:
value = n % 1000
temp = ""
# Handle 3 digit number
if value >= 100:
temp = units[value // 100] + " Hundred "
value %= 100
# Handle 2 digit number
if value >= 20:
temp += tens[value // 10] + " "
value %= 10
# Handle unit number
if value > 0:
temp += units[value] + " "
# Add the multiplier according to the group
temp += multiplier[group] + " "
# Add the result of this group to overall result
res = temp + res
n //= 1000
group += 1
# Remove trailing space
return res.strip()if name == "main": n = 2147483647 print(convertToWords(n))
C#
// C# program to convert number into words by breaking // it into groups of three
using System; using System.Collections.Generic;
class GfG { static string ConvertToWords(int n) { if (n == 0) return "Zero";
// Words for numbers 0 to 19
string[] units = {
"", "One", "Two", "Three",
"Four", "Five", "Six", "Seven",
"Eight", "Nine", "Ten", "Eleven",
"Twelve", "Thirteen", "Fourteen", "Fifteen",
"Sixteen", "Seventeen", "Eighteen", "Nineteen"
};
// Words for numbers multiple of 10
string[] tens = {
"", "", "Twenty", "Thirty", "Forty",
"Fifty", "Sixty", "Seventy", "Eighty", "Ninety"
};
string[] multiplier =
{"", "Thousand", "Million", "Billion"};
string res = "";
int group = 0;
// Process number in group of 1000s
while (n > 0) {
if (n % 1000 != 0) {
int value = n % 1000;
string temp = "";
// Handle 3 digit number
if (value >= 100) {
temp = units[value / 100] + " Hundred ";
value %= 100;
}
// Handle 2 digit number
if (value >= 20) {
temp += tens[value / 10] + " ";
value %= 10;
}
// Handle unit number
if (value > 0) {
temp += units[value] + " ";
}
// Add the multiplier according to the group
temp += multiplier[group] + " ";
// Add the this group result to overall result
res = temp + res;
}
n /= 1000;
group++;
}
// Remove trailing space
return res.Trim();
}
static void Main() {
int n = 2147483647;
Console.WriteLine(ConvertToWords(n));
}}
JavaScript
// JavaScript program to convert number into words by breaking // it into groups of three
function convertToWords(n) { if (n === 0) return "Zero";
// Words for numbers 0 to 19
const units = [
"", "One", "Two", "Three",
"Four", "Five", "Six", "Seven",
"Eight", "Nine", "Ten", "Eleven",
"Twelve", "Thirteen", "Fourteen", "Fifteen",
"Sixteen", "Seventeen", "Eighteen", "Nineteen"
];
// Words for numbers multiple of 10
const tens = [
"", "", "Twenty", "Thirty", "Forty",
"Fifty", "Sixty", "Seventy", "Eighty", "Ninety"
];
const multiplier = ["", "Thousand", "Million", "Billion"];
let res = "";
let group = 0;
// Process number in group of 1000s
while (n > 0) {
if (n % 1000 !== 0) {
let value = n % 1000;
let temp = "";
// Handle 3 digit number
if (value >= 100) {
temp = units[Math.floor(value / 100)] + " Hundred ";
value %= 100;
}
// Handle 2 digit number
if (value >= 20) {
temp += tens[Math.floor(value / 10)] + " ";
value %= 10;
}
// Handle unit number
if (value > 0) {
temp += units[value] + " ";
}
// Add the multiplier according to the group
temp += multiplier[group] + " ";
// Add the result of this group to overall result
res = temp + res;
}
n = Math.floor(n / 1000);
group++;
}
// Remove trailing space
return res.trim();}
const n = 2147483647; console.log(convertToWords(n));
`
Output
Two Billion One Hundred Forty Seven Million Four Hundred Eighty Three Thousand Six Hundred Forty Seven
**Time Complexity: O(log10(n)) - As we are dividing the number by a multiple of ten (like 1000, 100, 10), reducing the number logarithmically.
**Auxiliary Space: O(1)
[Approach 2] By Mapping Key Numeric Values with English Words
_The idea is to **store _the key numeric values, such as billion, million, thousand, hundred, tens, and units and their corresponding English words in **descending _order. We compare the given number with these values, starting from the **largest . If the number is **greater _than or equal to the current numeric value, we first add the word for the **quotient (number / numeric value) , then append the word for the **current numeric value (like "Billion", "Thousand", or "Hundred"), and finally append the word for the remainder ****(number % numeric value)** _recursively. This process continues until the entire number is converted to words.
For example, if the number is 203. So, the first key numeric value which is smaller than this number is 100.
- First, we add the quotient part = 203 / 100 = 2, result = "Two".
- Next, we append the word for key numeric value which is 100, result = "Two Hundred" .
- Finally, we append the word for remainder part = 203 % 100 = 3, so the final result is = "Two Hundred Three". C++ `
// C++ program to convert number into words by Mapping Key Numeric Values // with English Words
#include #include #include using namespace std;
string convertToWordsRec(int n, vector &values, vector &words) { string res = "";
// Iterating over all key Numeric values
for (int i = 0; i < values.size(); i++) {
int value = values[i];
string word = words[i];
// If the number is greater than or
// equal to the current numeric value
if (n >= value) {
// Append the quotient part
// If the number is greater than or equal to 100
// then only we need to handle that
if (n >= 100)
res += convertToWordsRec(n / value, values, words) + " ";
// Append the word for numeric value
res += word;
// Append the remainder part
if (n % value > 0)
res += " " + convertToWordsRec(n % value, values, words);
return res;
}
}
return res;}
string convertToWords(int n) { if (n == 0) return "Zero";
// Key Numeric values and their corresponding English words
vector<int> values = {1000000000, 1000000, 1000, 100, 90, 80, 70,
60, 50, 40, 30, 20, 19, 18, 17, 16, 15, 14,
13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
vector<string> words = {"Billion", "Million", "Thousand", "Hundred",
"Ninety", "Eighty", "Seventy", "Sixty", "Fifty",
"Forty", "Thirty", "Twenty", "Nineteen",
"Eighteen", "Seventeen", "Sixteen", "Fifteen",
"Fourteen", "Thirteen", "Twelve", "Eleven",
"Ten", "Nine", "Eight", "Seven", "Six", "Five",
"Four", "Three", "Two", "One"};
return convertToWordsRec(n, values, words);}
int main() { int n = 2147483647; cout << convertToWords(n) << endl; return 0; }
Java
// Java program to convert number into words by Mapping Key Numeric // Values with English Words
class GfG {
// Method to convert number into words recursively
static String convertToWordsRec(int n, int[] values, String[] words) {
String res = "";
// Iterating over all key Numeric values
for (int i = 0; i < values.length; i++) {
int value = values[i];
String word = words[i];
// If the number is greater than or equal to current numeric value
if (n >= value) {
// Append the quotient part
// If the number is greater than or equal to 100
// then only we need to handle that
if (n >= 100)
res += convertToWordsRec(n / value, values, words) + " ";
// Append the word for numeric value
res += word;
// Append the remainder part
if (n % value > 0)
res += " " + convertToWordsRec(n % value, values, words);
return res;
}
}
return res;
}
static String convertToWords(int n) {
if (n == 0)
return "Zero";
// Key Numeric values and their corresponding English words
int[] values = {
1000000000, 1000000, 1000, 100, 90, 80, 70,
60, 50, 40, 30, 20, 19, 18, 17, 16, 15, 14,
13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1
};
String[] words = {
"Billion", "Million", "Thousand", "Hundred",
"Ninety", "Eighty", "Seventy", "Sixty", "Fifty",
"Forty", "Thirty", "Twenty", "Nineteen",
"Eighteen", "Seventeen", "Sixteen", "Fifteen",
"Fourteen", "Thirteen", "Twelve", "Eleven",
"Ten", "Nine", "Eight", "Seven", "Six", "Five",
"Four", "Three", "Two", "One"
};
return convertToWordsRec(n, values, words);
}
public static void main(String[] args) {
int n = 2147483647;
System.out.println(convertToWords(n));
}}
Python
Python program to convert number into words by Mapping Key Numeric Values
with English Words
def convertToWordsRec(n, values, words): res = ""
# Iterating over all key Numeric values
for i in range(len(values)):
value = values[i]
word = words[i]
# If the number is greater than or equal to the current numeric value
if n >= value:
# Append the quotient part
# If the number is greater than or equal to 100
# then only we need to handle that
if n >= 100:
res += convertToWordsRec(n // value, values, words) + " "
# Append the word for numeric value
res += word
# Append the remainder part
if n % value > 0:
res += " " + convertToWordsRec(n % value, values, words)
return res
return resdef convertToWords(n): if n == 0: return "Zero"
# Key Numeric values and their corresponding English words
values = [1000000000, 1000000, 1000, 100, 90, 80, 70,
60, 50, 40, 30, 20, 19, 18, 17, 16, 15, 14,
13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1]
words = ["Billion", "Million", "Thousand", "Hundred",
"Ninety", "Eighty", "Seventy", "Sixty", "Fifty",
"Forty", "Thirty", "Twenty", "Nineteen",
"Eighteen", "Seventeen", "Sixteen", "Fifteen",
"Fourteen", "Thirteen", "Twelve", "Eleven",
"Ten", "Nine", "Eight", "Seven", "Six", "Five",
"Four", "Three", "Two", "One"]
return convertToWordsRec(n, values, words)if name == "main": n = 2147483647 print(convertToWords(n))
C#
// C# program to convert number into words by Mapping Key Numeric Values // with English Words
using System;
class GfG { static string convertToWordsRec(int n, int[] values, string[] words) { string res = "";
// Iterating over all key Numeric values
for (int i = 0; i < values.Length; i++) {
int value = values[i];
string word = words[i];
// If the number is greater than or equal to the current numeric value
if (n >= value) {
// Append the quotient part
// If the number is greater than or equal to 100
// then only we need to handle that
if (n >= 100)
res += convertToWordsRec(n / value, values, words) + " ";
// Append the word for numeric value
res += word;
// Append the remainder part
if (n % value > 0)
res += " " + convertToWordsRec(n % value, values, words);
return res;
}
}
return res;
}
static string convertToWords(int n) {
if (n == 0)
return "Zero";
// Key Numeric values and their corresponding English words
int[] values = {
1000000000, 1000000, 1000, 100, 90, 80, 70,
60, 50, 40, 30, 20, 19, 18, 17, 16, 15, 14,
13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1
};
string[] words = {
"Billion", "Million", "Thousand", "Hundred",
"Ninety", "Eighty", "Seventy", "Sixty", "Fifty",
"Forty", "Thirty", "Twenty", "Nineteen",
"Eighteen", "Seventeen", "Sixteen", "Fifteen",
"Fourteen", "Thirteen", "Twelve", "Eleven",
"Ten", "Nine", "Eight", "Seven", "Six", "Five",
"Four", "Three", "Two", "One"
};
return convertToWordsRec(n, values, words);
}
static void Main() {
int n = 2147483647;
Console.WriteLine(convertToWords(n));
}}
JavaScript
// JavaScript program to convert number into words by Mapping Key Numeric Values // with English Words
function convertToWordsRec(n, values, words) { let res = "";
// Iterating over all key Numeric values
for (let i = 0; i < values.length; i++) {
let value = values[i];
let word = words[i];
// If the number is greater than or equal to the current numeric value
if (n >= value) {
// Append the quotient part
// If the number is greater than or equal to 100
// then only we need to handle that
if (n >= 100)
res += convertToWordsRec(Math.floor(n / value), values, words) + " ";
// Append the word for numeric value
res += word;
// Append the remainder part
if (n % value > 0)
res += " " + convertToWordsRec(n % value, values, words);
return res;
}
}
return res;}
function convertToWords(n) { if (n === 0) return "Zero";
// Key Numeric values and their corresponding English words
const values = [1000000000, 1000000, 1000, 100, 90, 80, 70,
60, 50, 40, 30, 20, 19, 18, 17, 16, 15, 14,
13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1];
const words = ["Billion", "Million", "Thousand", "Hundred",
"Ninety", "Eighty", "Seventy", "Sixty", "Fifty",
"Forty", "Thirty", "Twenty", "Nineteen",
"Eighteen", "Seventeen", "Sixteen", "Fifteen",
"Fourteen", "Thirteen", "Twelve", "Eleven",
"Ten", "Nine", "Eight", "Seven", "Six", "Five",
"Four", "Three", "Two", "One"];
return convertToWordsRec(n, values, words);}
let n = 2147483647; console.log(convertToWords(n));
`
Output
Two Billion One Hundred Forty Seven Million Four Hundred Eighty Three Thousand Six Hundred Forty Seven
**Time Complexity: O(log10(n)) - As we are dividing the number by a key numeric value (typically by 1000, 100, etc.), reducing the number logarithmically with each call.
**Auxiliary Space: O(log10(n)) - Recursion stack size will be same as the total number of recursive calls.