202401181632
tags: #two-pointers #hash-map

var threeSum = function(nums) {
	nums.sort((a, b) => a - b);
	const res = [];
	for (let i = 0; i < nums.length; i++) {
		if (i > 0 && nums[i] === nums[i - 1]) {
			continue;
		}
		let start = i + 1;
		let end = nums.length - 1;
		while (start < end) {
			const sum = nums[i] + nums[start] + nums[end];
			if (sum === 0) {
				res.push([nums[i], nums[start], nums[end]]);
				while (start < end && nums[start] === nums[start + 1]) {
					start += 1;
				}
				while (start < end && nums[end] === nums[end - 1]) {
					end -= 1;
				}
				start += 1;
				end -= 1;
			}
			else if (sum < 0) {
				start += 1;
			}
			else {
				end -= 1;
			}
		}
	}
	return res;
};

Reference

https://leetcode.com/problems/3sum/