40:组合总和 II

src/main/java/leetcode/editor/cn/CombinationSumIi.java

@@ -0,0 +1,86 @@
+//给定一个数组 candidates 和一个目标数 target ，找出 candidates 中所有可以使数字和为 target 的组合。 
+//
+// candidates 中的每个数字在每个组合中只能使用一次。 
+//
+// 注意：解集不能包含重复的组合。 
+//
+// 
+//
+// 示例 1: 
+//
+// 
+//输入: candidates = [10,1,2,7,6,1,5], target = 8,
+//输出:
+//[
+//[1,1,6],
+//[1,2,5],
+//[1,7],
+//[2,6]
+//] 
+//
+// 示例 2: 
+//
+// 
+//输入: candidates = [2,5,2,1,2], target = 5,
+//输出:
+//[
+//[1,2,2],
+//[5]
+//] 
+//
+// 
+//
+// 提示: 
+//
+// 
+// 1 <= candidates.length <= 100 
+// 1 <= candidates[i] <= 50 
+// 1 <= target <= 30 
+// 
+// Related Topics 数组 回溯 👍 668 👎 0
+
+package leetcode.editor.cn;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+//40:组合总和 II
+class CombinationSumIi {
+    public static void main(String[] args) {
+        //测试代码
+        Solution solution = new CombinationSumIi().new Solution();
+    }
+
+    //力扣代码
+    //leetcode submit region begin(Prohibit modification and deletion)
+    class Solution {
+        public List<List<Integer>> combinationSum2(int[] candidates, int target) {
+            Arrays.sort(candidates);
+            List<List<Integer>> result = new ArrayList<>();
+            dfs(candidates, target, 0, result, new ArrayList<>());
+            return result;
+        }
+
+        private void dfs(int[] candidates, int target, int index, List<List<Integer>> result,
+                         List<Integer> list) {
+            if (target == 0) {
+                result.add(new ArrayList<>(list));
+                return;
+            }
+            if (index >= candidates.length || target < 0) {
+                return;
+            }
+            for (int i = index; i < candidates.length; i++) {
+                if (i - 1 < candidates.length && i > 0 && i > index && candidates[i] == candidates[i - 1]) {
+                    continue;
+                }
+                list.add(candidates[i]);
+                dfs(candidates, target - candidates[i], i + 1, result, list);
+                list.remove(list.size() - 1);
+            }
+        }
+    }
+//leetcode submit region end(Prohibit modification and deletion)
+
+}