题解 | #三数之和#

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 *
 * @param arr int整型一维数组
 * @return int整型二维数组
 */
function threeSum(arr) {
    // write code here
    arr.sort(function (a, b) {
        return a - b;
    });
    let result = [];
    for (let i = 0; i < arr.length - 2; i++) {
        if (i > 0 && arr[i] === arr[i - 1]) continue; // 避免重复
        let left = i + 1;
        let right = arr.length - 1;
        while (left < right) {
            let sum = arr[i] + arr[left] + arr[right];
            if (sum === 0) {
                result.push([arr[i], arr[left], arr[right]]);
                while (left < right && arr[left] === arr[left + 1]) left++;
                while (left < right && arr[right] === arr[right - 1]) right--;
                left++;
                right--;
            } else if (sum < 0) {
                left++;
            } else {
                right--;
            }
        }
    }
    return result;
}
module.exports = {
    threeSum: threeSum,
};