add comments for 432

fishercoder1534 · fishercoder1534 · commit 9a36136402d7 · 2021-03-28T11:23:44.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_423.java b/src/main/java/com/fishercoder/solutions/_423.java
@@ -60,4 +60,22 @@ public String originalDigits(String s) {
         }
     }
 
+    public static class Solution2 {
+        /**My original idea on 3/28/2021, similar to the above idea in Solution1:
+         *
+         * we can use signal characters to sort these unsorted characters out
+         1. z must be mapping to zero; 0
+         2. x -> six; 6
+         3. w -> two; 2
+         4. u -> four; 4
+         5. g -> eight; 8
+         6. only two digits have f: five and four, four is represented by the letter u, so the remaining f must form five; 5
+         7. only two digits have v: seven and five, five is done based on rule 6, so the remaining v must form seven; 7
+         8. only two digits have h: three and eight, eight is done based on rule 5, so the remaining h must form three; 3
+         9. four digits could have o: zero, one, two and four, since all the latter 3 digits have been done already, so the remaining o must form one; 1
+         10. all the rest of the unmapped characters must be able to form a multiple of nine; 9
+         11. then all 10 digits are sorted out
+         */
+    }
+
 }
