solutions: 17

number_letter_counts.rs

@@ -0,0 +1,83 @@
+const GENERIC: [&str; 20] = [
+    "",
+    "one",
+    "two",
+    "three",
+    "four",
+    "five",
+    "six",
+    "seven",
+    "eight",
+    "nine",
+    "ten",
+    "eleven",
+    "twelve",
+    "thirteen",
+    "fourteen",
+    "fifteen",
+    "sixteen",
+    "seventeen",
+    "eighteen",
+    "nineteen",
+];
+const SPECIAL: [&str; 11] = [
+    "",
+    "",
+    "twenty",
+    "thirty",
+    "forty",
+    "fifty",
+    "sixty",
+    "seventy",
+    "eighty",
+    "ninety",
+    "hundred",
+]; 
+
+fn translate(number: u64) -> String {
+    let mut result: String = "".to_string();
+
+    match number {
+        number if number < 20 => { result = GENERIC[(number) as usize].to_string(); },
+        number if number >= 20 && number < 100 => {
+            let number_string = number.to_string();
+            let tens = number_string.chars().nth(0).unwrap().to_digit(10).unwrap();
+            let ones = number_string.chars().nth(1).unwrap().to_digit(10).unwrap();
+
+            result = SPECIAL[tens as usize].to_owned()+GENERIC[(ones) as usize];
+        },
+        100 => { result = "onehundred".to_string(); }
+        number if number > 100 && number < 1000 => {
+            let number_string = number.to_string();
+            let hundreds = number_string.chars().nth(0).unwrap().to_digit(10).unwrap();
+            let tens = number_string.chars().nth(1).unwrap().to_digit(10).unwrap();
+            let ones = number_string.chars().nth(2).unwrap().to_digit(10).unwrap();
+
+            let combined = format!("{}{}", number_string.chars().nth(1).unwrap(), number_string.chars().nth(2).unwrap()).parse::<u64>().unwrap();
+
+            if combined < 20 {
+                if ones == 0 && tens == 0 {
+                    result = GENERIC[hundreds as usize].to_owned()+"hundred"+GENERIC[combined as usize];
+                } else {
+                    result = GENERIC[hundreds as usize].to_owned()+"hundredand"+GENERIC[combined as usize];
+                }
+            } else {
+                result = GENERIC[hundreds as usize].to_owned()+"hundredand"+SPECIAL[(tens) as usize]+GENERIC[(ones) as usize];
+            }
+        },
+        1000 => { result = "onethousand".to_string(); }
+        _ => {},
+    }
+
+    result
+}
+
+fn main() {
+    let mut total = 0;
+
+    for i in 1..=1000 {
+        total += translate(i).len();
+    }
+ 
+    println!("{}", total);
+}