## Algorithm

Problem Name: 273. Integer to English Words

Convert a non-negative integer `num` to its English words representation.

Example 1:

```Input: num = 123
Output: "One Hundred Twenty Three"
```

Example 2:

```Input: num = 12345
Output: "Twelve Thousand Three Hundred Forty Five"
```

Example 3:

```Input: num = 1234567
Output: "One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven"
```

Constraints:

• `0 <= num <= 231 - 1`

## Code Examples

### #1 Code Example with C Programming

```Code - C Programming```

``````
const char *tms[] = { "Billion", "Million",  "Thousand", "", "Hundred" };
const char *nx[] = { "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine" };
const char *n1x[] = { "Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen" };
const char *n2x[] = { "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety" };
​
#define APPEND(STR) do { \
strcat(p, STR); \
l = strlen(p); \
*(p + l) = ' '; \
p += l + 1; \
total += l + 1; \
f = 1; \
} while (0)
​
char* numberToWords(int num) {
char *buff, *p;
int sz, l, total;
int m, k, t, d = 1000000000;
int f, onex;

sz = 1000;
buff = calloc(sz, sizeof(char));
//assert(buff);
p = buff;

p[0] = 0;
total = 0;

k = num / d;
if (k) {
APPEND(nx[k - 1]);
APPEND(tms[0]);
}

num = num % d;
d = d / 1000;

t = 1;
while (num) {
m = num / d;
num = num % d;
d = d / 1000;

f = onex = 0;

k = m / 100;
m = m % 100;
if (k) {
APPEND(nx[k - 1]);
APPEND(tms[4]);
}

k = m / 10;
m = m % 10;
if (k == 1) {
onex = 1;
} else if (k) {
APPEND(n2x[k - 2]);
}

k = m;
if (onex) {
APPEND(n1x[k]);
} else if (k) {
APPEND(nx[k - 1]);
}

if (f && d) {
APPEND(tms[t]);
}
t ++;
}

if (total == 0) {
strcpy(buff, "Zero");
} else {
buff[total - 1] = 0;
}

//printf("%s\n", buff);

return buff;
}
``````
Copy The Code &

Input

cmd
num = 123

Output

cmd
"One Hundred Twenty Three"

### #2 Code Example with C++ Programming

```Code - C++ Programming```

``````
class Solution {
public:
string numberToWords(int num) {
if(num == 0) return "Zero";
vector < string>thousands({"", " Thousand", " Million", " Billion"});
string res = "";
int i = 0;
while(num){
if(num % 1000) res = helper(num % 1000) + thousands[i] + (res.size() ? " " : "") + res;
num /= 1000;
i++;
}
return res;
}

string helper(int num){
vector < string>lessThan20({"", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine","Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen"});
vector<string>tens({"", "", "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety"});
if(num >= 100) return lessThan20[num / 100] + " Hundred" + (num % 100 ? " ": "") + helper(num % 100);
else if(num >= 20) return tens[num / 10] + (num % 10 ? " ": "") + helper(num % 10);
else return lessThan20[num];
}
};
``````
Copy The Code &

Input

cmd
num = 123

Output

cmd
"One Hundred Twenty Three"

### #3 Code Example with Java Programming

```Code - Java Programming```

``````
class Solution {
private final String[] belowTen = new String[] {"", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine"};
private final String[] belowTwenty = new String[] {"Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen"};
private final String[] belowHundred = new String[] {"", "Ten", "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety"};

public String numberToWords(int num) {
if (num == 0) return "Zero";
return helper(num);
}

private String helper(int num) {
String result;

if (num  <  10) {
result = belowTen[num];
}
else if (num < 20) {
result = belowTwenty[num - 10];
}
else if (num  <  100) {
result = belowHundred[num / 10] + " " + helper(num % 10);
}
else if (num < 1000) {
result = helper(num / 100) + " Hundred " + helper(num % 100);
}
else if (num  <  1000000) {
result = helper(num / 1000) + " Thousand " + helper(num % 1000);
}
else if (num < 1000000000) {
result = helper(num / 1000000) + " Million " + helper(num % 1000000);
}
else {
result = helper(num/1000000000) + " Billion " + helper(num % 1000000000);
}

return result.trim();
}
}
``````
Copy The Code &

Input

cmd
num = 12345

Output

cmd
"Twelve Thousand Three Hundred Forty Five"

### #4 Code Example with Javascript Programming

```Code - Javascript Programming```

``````
const numberToWords = function(num) {
if (num === 0) return "Zero";
if (num  < = 20) return translations.get(num);
const result = [];

for (let [value, translation] of translations) {
const times = Math.floor(num / value);
if (times === 0) continue;
num -= times * value;
if (times === 1 && value >= 100) {
result.push("One", translation);
continue;
}
if (times === 1) {
result.push(translation);
continue;
}
result.push(numberToWords(times), translation);
}
return result.join(" ");
};

const translations = new Map([
[1000000000, "Billion"],
[1000000, "Million"],
[1000, "Thousand"],
[100, "Hundred"],
[90, "Ninety"],
[80, "Eighty"],
[70, "Seventy"],
[60, "Sixty"],
[50, "Fifty"],
[40, "Forty"],
[30, "Thirty"],
[20, "Twenty"],
[19, "Nineteen"],
[18, "Eighteen"],
[17, "Seventeen"],
[16, "Sixteen"],
[15, "Fifteen"],
[14, "Fourteen"],
[13, "Thirteen"],
[12, "Twelve"],
[11, "Eleven"],
[10, "Ten"],
[9, "Nine"],
[8, "Eight"],
[7, "Seven"],
[6, "Six"],
[5, "Five"],
[4, "Four"],
[3, "Three"],
[2, "Two"],
[1, "One"]
]);
``````
Copy The Code &

Input

cmd
num = 12345

Output

cmd
"Twelve Thousand Three Hundred Forty Five"

### #5 Code Example with Python Programming

```Code - Python Programming```

``````
class Solution:
def __init__(self):
self.lessThan20 = ["","One","Two","Three","Four","Five","Six","Seven","Eight","Nine","Ten","Eleven","Twelve","Thirteen","Fourteen","Fifteen","Sixteen","Seventeen","Eighteen","Nineteen"]
self.tens = ["","Ten","Twenty","Thirty","Forty","Fifty","Sixty","Seventy","Eighty","Ninety"]
self.thousands = ["","Thousand","Million","Billion"]

def numberToWords(self, num):
if not num:
return "Zero"
res = ""
for thousand in self.thousands:
if num % 1000:
res = self.helper(num%1000) + thousand + " " + res
num //= 1000
return res.strip()

def helper(self, num):
if not num:
return ""
elif num < 20:
return self.lessThan20[num] + " "
elif num < 100:
return self.tens[num//10] + " " + self.helper(num%10)
else:
return self.lessThan20[num//100] + " Hundred " + self.helper(num%100)
``````
Copy The Code &

Input

cmd
num = 1234567

Output

cmd
"One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven"

### #6 Code Example with C# Programming

```Code - C# Programming```

``````
namespace LeetCode
{
public class _0273_IntegerToEnglishWords
{
public string NumberToWords(int num)
{
if (num == 0) return "Zero";

int billion = num / 1000000000;
int million = (num - billion * 1000000000) / 1000000;
int thousand = (num - billion * 1000000000 - million * 1000000) / 1000;
int rest = num - billion * 1000000000 - million * 1000000 - thousand * 1000;

string result = "";
if (billion != 0) result = ThreeDigitsToString(billion) + " Billion";
if (million != 0)
{
if (!string.IsNullOrEmpty(result)) result += " ";
result += ThreeDigitsToString(million) + " Million";
}
if (thousand != 0)
{
if (!string.IsNullOrEmpty(result)) result += " ";
result += ThreeDigitsToString(thousand) + " Thousand";
}
if (rest != 0)
{
if (!string.IsNullOrEmpty(result)) result += " ";
result += ThreeDigitsToString(rest);
}
return result;
}

private string OneDigitToString(int num)
{
switch (num)
{
case 1: return "One";
case 2: return "Two";
case 3: return "Three";
case 4: return "Four";
case 5: return "Five";
case 6: return "Six";
case 7: return "Seven";
case 8: return "Eight";
case 9: return "Nine";
}
return "";
}

private string TwoDigitsLessThan20ToString(int num)
{
switch (num)
{
case 10: return "Ten";
case 11: return "Eleven";
case 12: return "Twelve";
case 13: return "Thirteen";
case 14: return "Fourteen";
case 15: return "Fifteen";
case 16: return "Sixteen";
case 17: return "Seventeen";
case 18: return "Eighteen";
case 19: return "Nineteen";
}
return "";
}

private string TenMultipleToString(int num)
{
switch (num)
{
case 2: return "Twenty";
case 3: return "Thirty";
case 4: return "Forty";
case 5: return "Fifty";
case 6: return "Sixty";
case 7: return "Seventy";
case 8: return "Eighty";
case 9: return "Ninety";
}
return "";
}

private string TwoDigitsToString(int num)
{
if (num == 0)
return "";
else if (num  <  10)
return OneDigitToString(num);
else if (num < 20)
return TwoDigitsLessThan20ToString(num);
else
{
int tenner = num / 10;
int rest = num - tenner * 10;
if (rest != 0)
return TenMultipleToString(tenner) + " " + OneDigitToString(rest);
else
return TenMultipleToString(tenner);
}
}

private string ThreeDigitsToString(int num)
{
int hundred = num / 100;
int rest = num - hundred * 100;
string res = "";
if (hundred * rest != 0)
res = OneDigitToString(hundred) + " Hundred " + TwoDigitsToString(rest);
else if ((hundred == 0) && (rest != 0))
res = TwoDigitsToString(rest);
else if ((hundred != 0) && (rest == 0))
res = OneDigitToString(hundred) + " Hundred";
return res;
}
}
}
``````
Copy The Code &

Input

cmd
num = 1234567

Output

cmd
"One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven"