Solved day 17 part 2

Author: Gentleman1983

build.gradle

@@ -4,7 +4,7 @@ plugins {
 
 // project meta data
 group 'de.havox_design.aoc2015'
-version '0.16.3'
+version '0.16.4'
 
 // Switch to gradle "all" distribution.
 wrapper {

day17/src/main/java/de/havox_design/aoc2015/day17/NotEnoughEggnod.java

@@ -29,12 +29,19 @@ public static int solvePart2(String fileName) {
         return instance.solvePart2();
     }
 
+    protected static int countLimitedCombinations(String fileName, int amountOfEggnod) {
+        NotEnoughEggnod instance = new NotEnoughEggnod(fileName);
+        int minContainerRequirement = instance.findMinimumContainerCount(instance.input, 0, amountOfEggnod, 0);
+        return instance.countWaysWithLimitedContainers(instance.input, 0, amountOfEggnod, 0, minContainerRequirement);
+    }
+
     public int solvePart1() {
         return countWays(input, 0, 150, 0);
     }
 
     public int solvePart2() {
-        return 0;
+        int minContainerRequirement = findMinimumContainerCount(input, 0, 150, 0);
+        return countWaysWithLimitedContainers(input, 0, 150, 0, minContainerRequirement);
     }
 
     private int countWays(List<Integer> containers, int startIndex, int target, int countSoFar) {
@@ -51,6 +58,36 @@ private int countWays(List<Integer> containers, int startIndex, int target, int
         }
     }
 
+    private int findMinimumContainerCount(List<Integer> containers, int startIndex, int target, int containerCount) {
+        if (target == 0) {
+            return containerCount;
+        } else if (target < 0) {
+            return Integer.MAX_VALUE;
+        } else {
+            int min = Integer.MAX_VALUE;
+            for (int i = startIndex; i < containers.size(); ++i) {
+                min = Math.min(min,
+                        findMinimumContainerCount(containers, i + 1, target - containers.get(i), containerCount + 1));
+            }
+            return min;
+        }
+    }
+
+    private int countWaysWithLimitedContainers(List<Integer> containers, int startIndex, int target, int countSoFar, int usableContainers) {
+        if (target == 0 && usableContainers >= 0) {
+            return 1;
+        } else if (target < 0 || usableContainers < 0) {
+            return 0;
+        } else {
+            int count = countSoFar;
+            for (int i = startIndex; i < containers.size(); ++i) {
+                count += countWaysWithLimitedContainers(containers, i + 1, target - containers.get(i), countSoFar,
+                        usableContainers - 1);
+            }
+            return count;
+        }
+    }
+
     private List<String> readData(String fileName) {
         return DataReader.readData(fileName, MainClass.class);
     }

day17/src/test/java/de/havox_design/aoc2015/day17/Day17Test.java

@@ -24,7 +24,19 @@ void testPart1(String fileName, int expectedNumberOfCombinations) {
 
     private static Stream<Arguments> getDataForPart1() {
         return Stream.of(
-                Arguments.of("part1sample.txt", 4)
+                Arguments.of("sample.txt", 4)
+        );
+    }
+
+    @ParameterizedTest
+    @MethodSource("getDataForPart2")
+    void testPart2(String fileName, int expectedNumberOfCombinations) {
+        Assertions.assertEquals(expectedNumberOfCombinations, NotEnoughEggnod.countLimitedCombinations(fileName, 25));
+    }
+
+    private static Stream<Arguments> getDataForPart2() {
+        return Stream.of(
+                Arguments.of("sample.txt", 3)
         );
     }
 }