Create Day13.java

Author: nsiwnf

Day13.java

@@ -0,0 +1,68 @@
+public class Day13 {
+
+  static int part1(int[] depths, int[] range) {
+    int[] scanner = new int[depths.length];
+
+    int severity = 0;
+    int i = 0;
+    int time = 0;
+    while (i < depths.length) {
+      if (time == depths[i]) {
+        if (scanner[i] == 0) {
+          severity += depths[i] * range[i];
+        }
+        i++;
+      }
+
+      // update scanner positions
+      for (int j = 0; j < scanner.length; j++) {
+        if (scanner[j] == range[j] - 1) {
+          scanner[j] *= -1;
+        }
+        scanner[j]++;
+      }
+
+      time++;
+    }
+
+    return severity;
+  }
+
+  static long part2(int[] depths, int[] range) {
+    long i = 0;
+    while (!part2(i, depths, range)) {
+      i++;
+    }
+    return i;
+  }
+
+  static boolean part2(long offset, int[] depths, int[] range) {
+    int i = 0;
+    long time = offset;
+    while (i < depths.length) {
+      if (time == depths[i] + offset) {
+        if (time % (2 * range[i] - 2) == 0) {
+          return false;
+        }
+        i++;
+      }
+
+      time++;
+    }
+
+    return true;
+  }
+
+  public static void main(String[] args) {
+    int[] depths = { 0, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48,
+        50, 52, 54, 58, 60, 62, 64, 66, 68, 72, 74, 76, 86, 88, 92, 94, 96, 98 };
+    int[] range = { 4, 2, 3, 4, 8, 5, 6, 6, 10, 8, 6, 9, 8, 6, 8, 8, 12, 12, 12, 12, 10, 12, 12, 14, 8, 14, 12, 14, 14,
+        14, 12, 14, 14, 12, 12, 14, 18, 17, 14, 20, 14, 14, 18, 18 };
+
+    // depths = new int[] { 0, 1, 4, 6 };
+    // range = new int[] { 3, 2, 4, 4 };
+
+    System.out.println(part1(depths, range));
+    System.out.println(part2(depths, range));
+  }
+}