commit

Author: 王俊超

.idea/modules.xml

@@ -0,0 +1,42 @@
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * @author: wangjunchao(王俊超)
+ * @time: 2018-09-28 15:15
+ **/
+public class Solution {
+    public List<List<Integer>> combinationSum2(int[] nums, int target) {
+        List<List<Integer>> list = new LinkedList<>();
+        Arrays.sort(nums);
+        backtrack(list, new LinkedList<>(), nums, target, 0);
+        return list;
+
+    }
+
+    /**
+     * @param list     结果集
+     * @param tempList 临时结果集
+     * @param nums     可选值数组
+     * @param remain   剩余值
+     * @param start    可选值的起始下标
+     */
+    private void backtrack(List<List<Integer>> list, List<Integer> tempList, int[] nums, int remain, int start) {
+        if (remain < 0) {
+            return;
+        } else if (remain == 0) {
+            list.add(new LinkedList<>(tempList));
+        } else {
+            for (int i = start; i < nums.length; i++) {
+                if (i > start && nums[i] == nums[i - 1]) {
+                    continue;
+                }
+                tempList.add(nums[i]);
+                // 数值不可以被重用
+                backtrack(list, tempList, nums, remain - nums[i], i + 1);
+                tempList.remove(tempList.size() - 1);
+            }
+        }
+    }
+}