CombinationSumII

Author: zgpeace

code/LeetCode/src/backtracking/CombinationSumII.java

@@ -0,0 +1,40 @@
+package backtracking;
+
+import java.util.*;
+
+// https://leetcode.com/problems/combination-sum-ii/
+public class CombinationSumII {
+
+  public static void main(String[] args) {
+    CombinationSumII obj = new CombinationSumII();
+    int[] candidates = {10,1,2,7,6,1,5};
+    int target = 8;
+    List<List<Integer>> resultList = obj.combinationSum2(candidates, target);
+    System.out.println("resultList >> " + Arrays.toString(resultList.toArray()));
+  }
+
+  public List<List<Integer>> combinationSum2(int[] candidates, int target) {
+    List<List<Integer>> resultList = new ArrayList<>();
+    Arrays.sort(candidates);
+    recursive(candidates, target, resultList, new ArrayList<Integer>(), 0);
+
+    return resultList;
+  }
+
+  public void recursive(int[] candidates, int target, List<List<Integer>> resultList, List<Integer> list, int start) {
+    if (target == 0) {
+      List<Integer> newList = new ArrayList<Integer>(list);
+
+      resultList.add(newList);
+    } else if (target > 0) {
+      for (int i = start; i < candidates.length && target >= candidates[i]; i++) {
+        if (i > start && candidates[i] == candidates[i - 1]) {
+          continue;
+        }
+        list.add(candidates[i]);
+        recursive(candidates, target - candidates[i], resultList, list, i + 1);
+        list.remove(list.size() - 1);
+      }
+    }
+  }
+}