Integer to English Words

Author: MaskRay

Diff for: README.md

@@ -2,7 +2,7 @@
 
 [LeetCode solutions](http://maskray.me/blog/2014-06-29-leetcode-solutions) gives some thoughts on selected problems.
 
-Solved 222/251 problems.
+Solved 224/256 problems.
 
 ## Database
 
@@ -12,9 +12,11 @@ See [database.md](database.md)
 
 | # | Title | Solution |
 |---| ----- | -------- |
+|273|[Integer to English Words](/problems/integer-to-english-words/)|[integer-to-english-words.cc](integer-to-english-words.cc)|
 |268|[Missing Number](/problems/missing-number/)|[missing-number.cc](missing-number.cc)|
 |264|[Ugly Number II](/problems/ugly-number-ii/)|[ugly-number-ii.cc](ugly-number-ii.cc)|
 |263|[Ugly Number](/problems/ugly-number/)|[ugly-number.cc](ugly-number.cc)|
+|260|[Single Number III](/problems/single-number-iii/)|[single-number-iii.cc](single-number-iii.cc)|
 |258|[Add Digits](/problems/add-digits/)|[add-digits.cc](add-digits.cc)|
 |257|[Binary Tree Paths](/problems/binary-tree-paths/)|[binary-tree-paths.cc](binary-tree-paths.cc)|
 |242|[Valid Anagram](/problems/valid-anagram/)|[valid-anagram.cc](valid-anagram.cc)|

Diff for: integer-to-english-words.cc

@@ -0,0 +1,24 @@
+// Integer to English Words
+class Solution
+{
+  string f(int x, int i, int v[], string n[]) {
+    if (! x) return "";
+    for (; x < v[i]; i++);
+    return (i < 4 ? f(x/v[i], i+1, v, n) : "") + n[i] + " " + f(x%v[i], i+1, v, n);
+  }
+public:
+  string numberToWords(int x) {
+    if (! x) return "Zero";
+    int v[] = {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 n[] = {"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"};
+    string r = f(x, 0, v, n);
+    r.pop_back();
+    return r;
+  }
+};