day 9

day9/src/main.rs

@@ -0,0 +1,76 @@
+fn main() {
+    let data = util::get_data("data.txt");
+
+    let mut results = Vec::new();
+    let mut results2 = Vec::new();
+
+    for i in 0..data.len() {
+        let r = process_row(&data[i]);
+
+        results.push(r.0);
+        results2.push(r.1);
+    }
+
+    println!("## Results part 1: {}", results.iter().sum::<i32>());
+    println!("## Results part 2: {}", results2.iter().sum::<i32>());
+}
+
+fn process_row(row: &String) -> (i32, i32) {
+    let numbers = util::get_numbers_from_str::<i32>(&row, " ");
+
+    let mut v: Vec<Vec<i32>> = Vec::new();
+    v.push(numbers);
+
+    let mut finished = false;
+    let mut i = 0;
+
+    while !finished {
+        let r = get_next_row(&v[i]);
+        v.push(r.0);
+
+        if r.1 {
+            finished = true;
+        }
+
+        i += 1;
+    }
+
+    return (value_from_processed(&v), value_from_processed_part2(&v));
+}
+
+fn value_from_processed_part2(v: &Vec<Vec<i32>>) -> i32 {
+    let mut tmp = 0;
+    for i in (1..v.len()).rev() {
+        let v_in = &v[i - 1];
+        tmp = v_in[0] - tmp;
+    }
+
+    return tmp;
+}
+
+fn value_from_processed(v: &Vec<Vec<i32>>) -> i32 {
+    let mut tmp = 0;
+    for i in (1..v.len()).rev() {
+        let v_in = &v[i - 1];
+        tmp += v_in[v_in.len() - 1];
+    }
+
+    return tmp;
+}
+
+fn get_next_row(row: &Vec<i32>) -> (Vec<i32>, bool) {
+    let mut next_row = Vec::new();
+    let mut only_zeroes = true;
+
+    for i in 0..(row.len() - 1) {
+        let v = row[i + 1] - row[i];
+
+        next_row.push(v);
+
+        if v != 0 {
+            only_zeroes = false;
+        }
+    }
+
+    return (next_row, only_zeroes);
+}