LeetCode15-三数之和
LeetCode15-三数之和
双指针+排序
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| public List<List<Integer>> threeSum(int[] nums) { Arrays.sort(nums); List<List<Integer>> res = new ArrayList<>(); for (int k = 0; k < nums.length - 2; k++) { if (nums[k] > 0) break; if (k > 0 && nums[k] == nums[k - 1]) continue; int l = k + 1, r = nums.length - 1; while (l < r) { int sum = nums[k] + nums[l] + nums[r]; if (sum < 0) { while (l < r && nums[l] == nums[++l]) ; } else if (sum > 0) { while (l < r && nums[r] == nums[--r]) ; } else { res.add(new ArrayList<>(Arrays.asList(nums[k], nums[l], nums[r]))); while (l < r && nums[l] == nums[++l]) ; while (l < r && nums[r] == nums[--r]) ; } } } return res; }
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