- 链接:https://leetcode-cn.com/problems/3sum/
代码
class Solution {
public List<List<Integer>> threeSum(int[] nums) {
Arrays.sort(nums);
List<List<Integer>> ans = new ArrayList();
int n = nums.length;
if (nums == null || n < 3) return ans;
for (int i = 0; i < n; ++i) {
if (nums[i] > 0) break;
if (i > 0 && nums[i] == nums[i - 1]) continue;
int l = i + 1;
int r = n - 1;
while (l < r) {
int sum = nums[i] + nums[l] + nums[r];
if (sum == 0) {
ans.add(Arrays.asList(nums[i], nums[l], nums[r]));
while (l < r && nums[l] == nums[l + 1]) l++;
while (l < r && nums[r] == nums[r - 1]) r--;
l++;
r--;
} else if (sum < 0) l++;
else r--;
}
}
return ans;
}
}