Integer To English Words Problem
Description
LeetCode Problem 273.
Convert a non-negative integer num to its English words representation.
Example 1:
1
2
Input: num = 123
Output: "One Hundred Twenty Three"
Example 2:
1
2
Input: num = 12345
Output: "Twelve Thousand Three Hundred Forty Five"
Example 3:
1
2
Input: num = 1234567
Output: "One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven"
Example 4:
1
2
Input: num = 1234567891
Output: "One Billion Two Hundred Thirty Four Million Five Hundred Sixty Seven Thousand Eight Hundred Ninety One"
Constraints:
- 0 <= num <= 2^31 - 1
Sample C++ Code
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
class Solution {
public:
string digits[20] = {"Zero", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen"};
string tens[10] = {"Zero", "Ten", "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety"};
string int2string(int n) {
if (n >= 1000000000) {
return int2string(n / 1000000000) + " Billion" + int2string(n % 1000000000);
} else if (n >= 1000000) {
return int2string(n / 1000000) + " Million" + int2string(n % 1000000);
} else if (n >= 1000) {
return int2string(n / 1000) + " Thousand" + int2string(n % 1000);
} else if (n >= 100) {
return int2string(n / 100) + " Hundred" + int2string(n % 100);
} else if (n >= 20) {
return " " + tens[n / 10] + int2string(n % 10);
} else if (n >= 1) {
return " " + digits[n];
} else {
return "";
}
}
string numberToWords(int num) {
if (num == 0) {
return "Zero";
} else {
string ret = int2string(num);
return ret.substr(1, ret.length() - 1);
}
}
};