Finished day 1 aoc 2023

advent_of_code/2023/1/src/main.rs

@@ -21,6 +21,111 @@ fn solve_1(input: &str) -> u32 {
         .sum()
 }
 
+fn digitify(chars: &str) -> u32 {
+    let mut chars_left = &chars[..];
+
+    while chars_left.len() > 0 {
+        if chars_left.len() >= 3 {
+            if let Some(digit) = chars_left.chars().next().unwrap().to_digit(10) {
+                return digit;
+            } else if &chars_left[0..3] == "one" {
+                return 1;
+            } else if &chars_left[0..3] == "two" {
+                return 2;
+            } else if &chars_left[0..3] == "six" {
+                return 6;
+            } else if chars_left.len() >= 4 {
+                if &chars_left[0..4] == "four" {
+                    return 4;
+                } else if &chars_left[0..4] == "five" {
+                    return 5;
+                } else if &chars_left[0..4] == "nine" {
+                    return 9;
+                } else if chars_left.len() >= 5 {
+                    if &chars_left[0..5] == "three" {
+                        return 3;
+                    } else if &chars_left[0..5] == "seven" {
+                        return 7;
+                    } else if &chars_left[0..5] == "eight" {
+                        return 8;
+                    } else {
+                        chars_left = &chars_left[1..];
+                    }
+                } else {
+                    chars_left = &chars_left[1..];
+                }
+            } else {
+                chars_left = &chars_left[1..];
+            }
+        } else if let Some(digit) = chars_left.chars().next().unwrap().to_digit(10) {
+            return digit;
+        } else {
+            chars_left = &chars_left[1..];
+        }
+    }
+
+    return 0;
+}
+
+fn digitify_backwards(line: &str) -> u32 {
+    let chars_left = line.chars().rev().collect::<String>();
+    let mut chars_left = chars_left.as_str();
+
+    while chars_left.len() > 0 {
+        if chars_left.len() >= 3 {
+            if let Some(digit) = chars_left.chars().next().unwrap().to_digit(10) {
+                return digit;
+            } else if &chars_left[0..3] == "eno" {
+                return 1;
+            } else if &chars_left[0..3] == "owt" {
+                return 2;
+            } else if &chars_left[0..3] == "xis" {
+                return 6;
+            } else if chars_left.len() >= 4 {
+                if &chars_left[0..4] == "ruof" {
+                    return 4;
+                } else if &chars_left[0..4] == "evif" {
+                    return 5;
+                } else if &chars_left[0..4] == "enin" {
+                    return 9;
+                } else if chars_left.len() >= 5 {
+                    if &chars_left[0..5] == "eerht" {
+                        return 3;
+                    } else if &chars_left[0..5] == "neves" {
+                        return 7;
+                    } else if &chars_left[0..5] == "thgie" {
+                        return 8;
+                    } else {
+                        chars_left = &chars_left[1..];
+                    }
+                } else {
+                    chars_left = &chars_left[1..];
+                }
+            } else {
+                chars_left = &chars_left[1..];
+            }
+        } else if let Some(digit) = chars_left.chars().next().unwrap().to_digit(10) {
+            return digit;
+        } else {
+            chars_left = &chars_left[1..];
+        }
+    }
+
+    return 0;
+}
+
+fn solve_2(input: &str) -> u32 {
+    input
+        .lines()
+        .map(|l| {
+            let first = digitify(&l[..]);
+            let last = digitify_backwards(&l[..]);
+
+            first * 10 + last
+        })
+        .sum()
+}
+
 fn main() {
     println!("Hello, this is Patrick!");
 
@@ -29,6 +134,10 @@ fn main() {
     let result_1 = solve_1(input_txt);
 
     println!("The sum of all calibration values is {}", result_1);
+
+    let result_2 = solve_2(input_txt);
+
+    println!("The sum of all improved calibration values is {}", result_2);
 }
 
 #[cfg(test)]
@@ -41,4 +150,11 @@ mod tests {
 
         assert_eq!(solve_1(test_input), 142);
     }
+
+    #[test]
+    fn test_2() {
+        let test_input = include_str!("../test2.txt");
+
+        assert_eq!(solve_2(test_input), 281);
+    }
 }