16.8. int to english

moderate problems chapter

16. Moderate problems/16.8. english_int.md

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+# 16.8. English int
+
+## Given any integer, print an english phrase that describes the integer
+
+> example:
+
+* input = 1234
+* output = "one thousand two hundred thirty four"
+
+## First idea
+
+Two tasks here, 1. int to char, and 2. int to thousand/hundred thirt(y) whatever. what about 11, 12, 35?
+
+```python
+inttochar = {
+    1: "one",
+    2: "two",
+    3: "three",
+    4: "four",
+    5: "five",
+    6: "six",
+    7: "seven",
+    8: "eight",
+    9: "nine"
+}
+
+inttodec = {
+    10: "ten",
+    11: "eleven",
+    12: "twelve",
+    3: "thir",
+    5: "fif"
+}
+
+inttoext = {
+    1: "teen",
+    0: "ty"
+}
+```
+
+This isn't a difficult problem, it's just cumbersome and long to make good-looking code.

16. Moderate problems/16.8. english_int.py

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+import unittest
+
+inttochar = {
+    1: "one",
+    2: "two",
+    3: "three",
+    4: "four",
+    5: "five",
+    6: "six",
+    7: "seven",
+    8: "eight",
+    9: "nine"
+}
+
+inttodec = {
+    10: "ten",
+    11: "eleven",
+    12: "twelve",
+    3: "thir",
+    4: "for",
+    5: "fif"
+}
+
+inttoext = {
+    1: "teen",
+    0: "ty"
+}
+
+def inttostrings(num, numlst):
+
+    ret = ""
+    if numlst[0] == 1:
+        if num in inttodec:
+            return inttodec[num]
+        if numlst[1] in inttodec:
+            return inttodec[numlst[1]] + inttoext[1]
+        else:
+            return inttochar[numlst[1]] + inttoext[1]
+    if numlst[0] in inttodec:
+        if numlst[0] != 0:
+            ret += inttodec[numlst[0]] + inttoext[0] + " "
+        return ret + inttochar[numlst[1]]
+    if numlst[0] != 0:
+            ret += inttochar[numlst[0]] + inttoext[0] + " "
+    return ret + inttochar[numlst[1]]
+
+def int_to_eng(num):
+
+    if num < 0:
+        return -1
+    if num == 0:
+        return "zero"
+    if num < 10:
+        return inttochar[num]
+    
+    res = ""
+    numlst = list(map(int, str(num)))
+
+    for i in range(len(numlst)-1):
+        numlst[-2-i] = inttostrings(num, numlst[-2-i:])
+        numlst.pop(-1)
+
+    return "".join(numlst)
+
+
+class Test(unittest.TestCase):
+    data = [(12, "twelve"),
+            (16, "sixteen"),
+            (45, "forty five"),
+            (33, "thirty three")]
+
+    def test_rotate_matrix(self):
+        for test_num, expected in self.data:
+            actual = int_to_eng(test_num)
+            self.assertEqual(actual, expected)
+
+if __name__ == "__main__":
+    unittest.main()