1 files changed, 117 insertions, 0 deletions
diff --git a/day03/day03.java b/day03/day03.java
new file mode 100644
index 0000000..4d4caa9
--- /dev/null
+++ b/day03/day03.java
@@ -0,0 +1,117 @@
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.util.ArrayList;
+import java.util.regex.Pattern;
+import java.util.regex.Matcher;
+
+class Number {
+  int row, colstart, colend, value;
+
+  public Number(int row, int colstart, int colend, int value) {
+    this.row = row;
+    this.colstart = colstart;
+    this.colend = colend;
+    this.value = value;
+  }
+
+  public String toString() {
+    return "[" + this.row + ", " + this.colstart + "-" + this.colend + "]: " + this.value;
+  }
+}
+
+class Symbol {
+  int row, col;
+  String symbol;
+
+  public Symbol(int row, int col, String symbol) {
+    this.row = row;
+    this.col = col;
+    this.symbol = symbol;
+  }
+
+  public String toString() {
+    return "[" + this.row + ", " + this.col + "]: " + this.symbol;
+  }
+}
+
+public class day03 {
+  public static void main(String args[]) throws IOException {
+    RandomAccessFile input = new RandomAccessFile("input", "r");
+    System.out.println("Day 01 Part 1: " + part1(input));
+    input.seek(0);
+    System.out.println("Day 01 Part 2: " + part2(input));
+    input.close();
+  }
+
+  public static String part1(RandomAccessFile input) throws IOException {
+    String line;
+    int row = 0;
+    ArrayList<Number> numbers = new ArrayList<>();
+    ArrayList<Symbol> symbols = new ArrayList<>();
+
+    while ((line = input.readLine()) != null) {
+      getNumbers(numbers, row, line);
+      getSymbols(symbols, row, line);
+      row += 1;
+    }
+
+    int tot = 0;
+    for (Number num: numbers) {
+      boolean part = false;
+      for (Symbol sym: symbols) {
+        for (int col = num.colstart - 1; col <= num.colend + 1; col++) {
+          if (sym.row == num.row - 1 && sym.col == col) {
+            part = true;
+          }
+          if (sym.row == num.row + 1 && sym.col == col) {
+            part = true;
+          }
+        }
+        if (sym.row == num.row && sym.col == num.colstart - 1) {
+          part = true;
+        }
+        if (sym.row == num.row && sym.col == num.colend + 1) {
+          part = true;
+        }
+      }
+      if (part) {
+        tot += num.value;
+      }
+    }
+
+    return Integer.toString(tot);
+  }
+
+  private static void getNumbers(ArrayList<Number> numbers, int row, String line) {
+    Pattern pat = Pattern.compile("\\d+");
+    Matcher mat = pat.matcher(line);
+    while (mat.find()) {
+      numbers.add(
+        new Number(
+          row,
+          mat.start(),
+          mat.end() - 1,
+          Integer.parseInt(mat.group())
+        )
+      );
+    }
+  }
+
+  private static void getSymbols(ArrayList<Symbol> symbols, int row, String line) {
+    Pattern pat = Pattern.compile("[^0-9.]");
+    Matcher mat = pat.matcher(line);
+    while (mat.find()) {
+      symbols.add(
+        new Symbol(
+          row,
+          mat.start(),
+          mat.group()
+        )
+      );
+    }
+  }
+
+  public static String part2(RandomAccessFile input) throws IOException {
+    return "WIP";
+  }
+}