advent of code 2023, days 1-4

src/main/java/com/marginallyclever/adventofcode/Day1.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day1.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import java.io.*;
 import java.util.ArrayList;

src/main/java/com/marginallyclever/adventofcode/Day10.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day10.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;

src/main/java/com/marginallyclever/adventofcode/Day11.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day11.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;

src/main/java/com/marginallyclever/adventofcode/Day12.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day12.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;

src/main/java/com/marginallyclever/adventofcode/Day13.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day13.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;

src/main/java/com/marginallyclever/adventofcode/Day2.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day2.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;

src/main/java/com/marginallyclever/adventofcode/Day3.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day3.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;

src/main/java/com/marginallyclever/adventofcode/Day4.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day4.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;

src/main/java/com/marginallyclever/adventofcode/Day5.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day5.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;

src/main/java/com/marginallyclever/adventofcode/Day6.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day6.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import org.json.JSONObject;
 

src/main/java/com/marginallyclever/adventofcode/Day8.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day8.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import javax.vecmath.Point2d;
 import javax.vecmath.Vector2d;

src/main/java/com/marginallyclever/adventofcode/Day9.java → src/main/java/com/marginallyclever/adventofcode/y2022/Day9.java

@@ -1,4 +1,4 @@
-package com.marginallyclever.adventofcode;
+package com.marginallyclever.adventofcode.y2022;
 
 import javax.vecmath.Point2d;
 import javax.vecmath.Vector2d;

src/main/java/com/marginallyclever/adventofcode/y2023/Day1.java

@@ -0,0 +1,76 @@
+package com.marginallyclever.adventofcode.y2023;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class Day1 {
+
+    public static void main(String[] args) {
+        Day1 me = new Day1();
+        me.processFile("day1.txt");
+    }
+
+    private void processFile(String filename) {
+        try (BufferedReader br = new BufferedReader(new InputStreamReader(new BufferedInputStream(Day1.class.getResourceAsStream(filename))))) {
+            String line;
+            while ((line = br.readLine()) != null) {
+                processLine(line);
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    int sum = 0;
+
+    private void processLine(String line) {
+        int value=0;
+        // scan forward
+        for(int i=0;i<line.length();++i) {
+            Character c = line.charAt(i);
+            if(Character.isDigit(c)) {
+                value = Character.getNumericValue(c)*10;
+                System.out.println(c+"="+value);
+                break;
+            }
+            int j = matchDigitName(line.substring(i));
+            if(j!=-1) {
+                value = j*10;
+                System.out.println(line.substring(i)+"="+value);
+                break;
+            }
+        }
+        // scan backward
+        for(int i=line.length()-1;i>=0;--i) {
+            Character c = line.charAt(i);
+            if(Character.isDigit(c)) {
+                value += Character.getNumericValue(c);
+                System.out.println(c+"="+value);
+                break;
+            }
+            int j = matchDigitName(line.substring(i));
+            if(j!=-1) {
+                value += j;
+                System.out.println(line.substring(i)+"="+value);
+                break;
+            }
+        }
+        sum += value;
+        System.out.println("sum="+sum);
+    }
+
+    private int matchDigitName(String substring) {
+        if(substring.startsWith("one")) return 1;
+        if(substring.startsWith("two")) return 2;
+        if(substring.startsWith("three")) return 3;
+        if(substring.startsWith("four")) return 4;
+        if(substring.startsWith("five")) return 5;
+        if(substring.startsWith("six")) return 6;
+        if(substring.startsWith("seven")) return 7;
+        if(substring.startsWith("eight")) return 8;
+        if(substring.startsWith("nine")) return 9;
+        return -1;
+    }
+}

src/main/java/com/marginallyclever/adventofcode/y2023/Day2.java

@@ -0,0 +1,80 @@
+package com.marginallyclever.adventofcode.y2023;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class Day2 {
+
+    public static void main(String[] args) {
+        Day2 me = new Day2();
+        me.processFile("day2.txt");
+    }
+
+    private void processFile(String filename) {
+        try (BufferedReader br = new BufferedReader(new InputStreamReader(new BufferedInputStream(Day2.class.getResourceAsStream(filename))))) {
+            String line;
+            while ((line = br.readLine()) != null) {
+                processLine(line);
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    int sum = 0;
+    final int maxR = 12;
+    final int maxG = 13;
+    final int maxB = 14;
+
+    /**
+     * line is in format
+     * <pre>Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+     * Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue</pre>
+     */
+    private void processLine(String line) {
+        // read the header
+        if(!line.startsWith("Game ")) {
+            throw new RuntimeException("Expected line to start with 'Game ' but got '"+line+"'");
+        }
+        line = line.substring(5);
+        int colon = line.indexOf(":");
+        String s1 = line.substring(0,colon);
+        int gameNumber = Integer.parseInt(s1);
+        System.out.println("Game "+gameNumber);
+        line = line.substring(colon+1);
+
+        int r=0;
+        int g=0;
+        int b=0;
+
+        // split by `;`
+        String [] parts = line.split(";");
+        for(String part : parts) {
+            // split part by `,`
+            String [] colorSection = part.split(",");
+            for(String section : colorSection) {
+                section = section.trim();
+                // split section by ' '
+                String [] colorCount = section.split(" ");
+                int count = Integer.parseInt(colorCount[0]);
+                String colorName = colorCount[1];
+
+                switch(colorName) {
+                    case "red": r = count;  break;
+                    case "green": g = count;  break;
+                    case "blue": b = count;   break;
+                    default: throw new RuntimeException("Unknown color '"+colorName+"'");
+                }
+            }
+            if(r>maxR) return;
+            if(g>maxG) return;
+            if(b>maxB) return;
+        }
+        System.out.println("  red="+r+" green="+g+" blue="+b);
+        System.out.println("Game "+gameNumber+" is valid.");
+        sum += gameNumber;
+        System.out.println("sum is "+sum);
+    }
+}

src/main/java/com/marginallyclever/adventofcode/y2023/Day2b.java

@@ -0,0 +1,82 @@
+package com.marginallyclever.adventofcode.y2023;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class Day2b {
+
+    public static void main(String[] args) {
+        Day2b me = new Day2b();
+        me.processFile("day2.txt");
+    }
+
+    private void processFile(String filename) {
+        try (BufferedReader br = new BufferedReader(new InputStreamReader(new BufferedInputStream(Day2b.class.getResourceAsStream(filename))))) {
+            String line;
+            while ((line = br.readLine()) != null) {
+                processLine(line);
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    int sum = 0;
+    int minR = 0;
+    int minG = 0;
+    int minB = 0;
+
+    /**
+     * line is in format
+     * <pre>Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+     * Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue</pre>
+     */
+    private void processLine(String line) {
+        // read the header
+        if(!line.startsWith("Game ")) {
+            throw new RuntimeException("Expected line to start with 'Game ' but got '"+line+"'");
+        }
+        line = line.substring(5);
+        int colon = line.indexOf(":");
+        String s1 = line.substring(0,colon);
+        int gameNumber = Integer.parseInt(s1);
+        System.out.println("Game "+gameNumber);
+        line = line.substring(colon+1);
+
+        minR = minG = minB = 0;
+        int r=0;
+        int g=0;
+        int b=0;
+
+        // split by `;`
+        String [] parts = line.split(";");
+        for(String part : parts) {
+            // split part by `,`
+            String [] colorSection = part.split(",");
+            for(String section : colorSection) {
+                section = section.trim();
+                // split section by ' '
+                String [] colorCount = section.split(" ");
+                int count = Integer.parseInt(colorCount[0]);
+                String colorName = colorCount[1];
+
+                switch(colorName) {
+                    case "red": r = count;  break;
+                    case "green": g = count;  break;
+                    case "blue": b = count;   break;
+                    default: throw new RuntimeException("Unknown color '"+colorName+"'");
+                }
+            }
+            if(r>minR) minR = r;
+            if(g>minG) minG = g;
+            if(b>minB) minB = b;
+        }
+        System.out.println("  red="+minR+" green="+minG+" blue="+minB);
+        int power = minR*minG*minB;
+        System.out.println("Game "+gameNumber+" power is "+power);
+        sum += power;
+        System.out.println("sum is "+sum);
+    }
+}