day 3 java

day03.java

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+import java.io.*;
+import java.util.*;
+import java.util.regex.*;
+
+import static java.lang.Integer.parseInt;
+import static java.lang.System.in;
+import static java.lang.System.out;
+
+public class day03 {
+    public static void main(String[] args) {
+        var cmd = Pattern.compile("mul\\((\\d+),(\\d+)\\)|do\\(\\)|don't\\(\\)");
+        var muls = new int[]{0, 0};
+        var _do = new boolean[]{true};
+        new BufferedReader(new InputStreamReader(in)).lines().forEach(line -> {
+            new Scanner(line).findAll(cmd).forEach(match -> {
+                if (match.group(0).startsWith("mul")) {
+                    var n1 = parseInt(match.group(1));
+                    var n2 = parseInt(match.group(2));
+                    muls[0] += n1 * n2;
+                    if (_do[0]) { muls[1] += n1 * n2; }
+                } else {
+                    _do[0] = "do()".equals(match.group(0));
+                }
+            });
+        });
+        out.printf("%d %d\n", muls[0], muls[1]);
+    }
+}