📚 3.三数之和

💻 代码实现

/**
 * @url https://leetcode.cn/problems/3sum/description/?envType=study-plan-v2&envId=top-100-liked
 */

/**
 * @param {number[]} nums
 * @return {number[][]}
 */
var threeSum = function (nums) {
    nums.sort((a, b) => a - b)
    const res = []
    for (let i = 0; i < nums.length - 1; i++) {
        if (i > 0 && nums[i] === nums[i - 1]) continue
        let left = i + 1, right = nums.length - 1
        while (left < right) {
            const sum = nums[left] + nums[right] + nums[i]
            if (sum === 0) {
                while (nums[left] === nums[left + 1]) left++ // ps: 这里避免相同的元素
                while (nums[right] === nums[right - 1]) right-- // ps: 这里避免相同的元素
                res.push([nums[left], nums[right], nums[i]])
                left++
                right--
            }
            if (sum < 0) {
                left++
            }
            if (sum > 0) {
                right--
            }
        }
    }
    return res
};