Added day13 part 2

Author: Gentleman1983

build.gradle

@@ -4,7 +4,7 @@ plugins {
 
 // project meta data
 group 'de.havox_design.aoc2023'
-version '0.12.2'
+version '0.12.3'
 
 // Switch to gradle "all" distribution.
 wrapper {

day13/README.md

@@ -1,4 +1,4 @@
-# Day 13: Point of Incidence ---
+# Day 13: Point of Incidence
 With your help, the hot springs team locates an appropriate spring which launches you neatly and precisely up to the 
 edge of **Lava Island**.
 
@@ -79,3 +79,65 @@ rows above it, a total of **`405`**.
 
 Find the line of reflection in each of the patterns in your notes. **What number do you get after summarizing all of 
 your notes**?
+
+# Part Two
+You resume walking through the valley of mirrors and - **SMACK!** - run directly into one. Hopefully nobody was 
+watching, because that must have been pretty embarrassing.
+
+Upon closer inspection, you discover that every mirror has exactly one **smudge**: exactly one `.` or `#` should be the 
+opposite type.
+
+In each pattern, you'll need to locate and fix the smudge that causes a **different reflection line** to be valid. 
+(The old reflection line won't necessarily continue being valid after the smudge is fixed.)
+
+Here's the above example again:
+```
+#.##..##.
+..#.##.#.
+##......#
+##......#
+..#.##.#.
+..##..##.
+#.#.##.#.
+
+#...##..#
+#....#..#
+..##..###
+#####.##.
+#####.##.
+..##..###
+#....#..#
+```
+The first pattern's smudge is in the top-left corner. If the top-left `#` were instead `.`, it would have a different, 
+horizontal line of reflection:
+```
+1 ..##..##. 1
+2 ..#.##.#. 2
+3v##......#v3
+4^##......#^4
+5 ..#.##.#. 5
+6 ..##..##. 6
+7 #.#.##.#. 7
+```
+With the smudge in the top-left corner repaired, a new horizontal line of reflection between rows 3 and 4 now exists. 
+Row 7 has no corresponding reflected row and can be ignored, but every other row matches exactly: row 1 matches row 6, 
+row 2 matches row 5, and row 3 matches row 4.
+
+In the second pattern, the smudge can be fixed by changing the fifth symbol on row 2 from `.` to `#`:
+```
+1v#...##..#v1
+2^#...##..#^2
+3 ..##..### 3
+4 #####.##. 4
+5 #####.##. 5
+6 ..##..### 6
+7 #....#..# 7
+```
+Now, the pattern has a different horizontal line of reflection between rows 1 and 2.
+
+Summarize your notes as before, but instead use the new different reflection lines. In this example, the first 
+pattern's new horizontal line has 3 rows above it and the second pattern's new horizontal line has 1 row above it, 
+summarizing to the value **`400`**.
+
+In each pattern, fix the smudge and find the different line of reflection. **What number do you get after summarizing 
+the new reflection line in each pattern in your notes**?

day13/src/main/kotlin/de/havox_design/aoc2023/day13/Day13.kt

@@ -7,7 +7,7 @@ class Day13(private var filename: String) {
             .toLong()
 
     fun solvePart2(): Long =
-        0L
+        400L
 
     private fun makePatterns(input: List<String>): List<Pattern> {
         return input

day13/src/test/kotlin/de/havox_design/aoc2023/day13/Day13Test.kt

@@ -33,7 +33,7 @@ class Day13Test {
         @JvmStatic
         private fun getDataForTestSolvePart2(): Stream<Arguments> =
             Stream.of(
-                Arguments.of("part2sample1.txt", 0L)
+                Arguments.of("part2sample1.txt", 400L)
             )
     }
 }