2017/05

2017/05/src/main.rs

@@ -0,0 +1,87 @@
+use std::io::{self, Read};
+
+
+fn process_one(mut data: Vec<i64>) -> usize {
+    let mut index: i64 = 0;
+    let mut steps = 0;
+
+    loop {
+        let addr = data[index as usize];
+
+        data[index as usize] += 1;
+
+        index += addr;
+        steps += 1;
+
+        if index < 0 || index as usize >= data.len() {
+            break;
+        }
+    }
+
+    steps
+}
+
+fn process_two(mut data: Vec<i64>) -> usize {
+    let mut index: i64 = 0;
+    let mut steps = 0;
+
+    loop {
+        if index < 0 || index as usize >= data.len() {
+            break;
+        }
+
+        let addr = data[index as usize];
+
+        data[index as usize] += if addr < 3 { 1 } else { -1 };
+
+        index += addr;
+        steps += 1;
+    }
+
+    steps
+}
+
+fn parse(input: &str) -> Vec<i64> {
+    input.lines().filter_map(|line| line.parse().ok()).collect()
+}
+
+
+fn main() {
+    let mut input = String::new();
+
+    io::stdin()
+        .read_to_string(&mut input)
+        .expect("faild to read input");
+
+    let data = parse(&input);
+
+    println!("part_one={}", process_one(data.clone()));
+    println!("part_two={}", process_two(data));
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse() {
+        let input = "0\n\
+                     3\n\
+                     0\n\
+                     1\n\
+                     -3";
+
+        assert_eq!(parse(input), vec![0, 3, 0, 1, -3]);
+    }
+
+    #[test]
+    fn test_process_one() {
+        assert_eq!(process_one(vec![0, 3, 0, 1, -3]), 5);
+    }
+
+    #[test]
+    fn test_process_two() {
+        assert_eq!(process_two(vec![0, 3, 0, 1, -3]), 10);
+    }
+}