添加0015.三数之和

添加0015.三数之和

problems/0015.三数之和.md

@@ -178,7 +178,44 @@ public:
 
 
 Java：
+```Java
+class Solution {
+    public List<List<Integer>> threeSum(int[] nums) {
+        List<List<Integer>> result = new ArrayList<>();
+        Arrays.sort(nums);
 
+        for (int i = 0; i < nums.length; i++) {
+            if (nums[i] > 0) {
+                return result;
+            }
+
+            if (i > 0 && nums[i] == nums[i - 1]) {
+                continue;
+            }
+
+            int left = i + 1;
+            int right = nums.length - 1;
+            while (right > left) {
+                int sum = nums[i] + nums[left] + nums[right];
+                if (sum > 0) {
+                    right--;
+                } else if (sum < 0) {
+                    left++;
+                } else {
+                    result.add(Arrays.asList(nums[i], nums[left], nums[right]));
+
+                    while (right > left && nums[right] == nums[right - 1]) right--;
+                    while (right > left && nums[left] == nums[left + 1]) left++;
+                    
+                    right--;
+                    left++;
+                }
+            }
+        }
+        return result;
+    }
+}
+```
 
 Python：