合并多个数组并将公共元素数组作为输出

function mergeAndFindCommonArrays(arrays) {
    let commonElements = [];

    for (let i = 0; i < arrays[0].length; i++) {
        let element = arrays[0][i];
        let isInAllArrays = true;

        for (let j = 1; j < arrays.length; j++) {
            if (!arrays[j].includes(element)) {
                isInAllArrays = false;
                break;
            }
        }

        if (isInAllArrays && !commonElements.includes(element)) {
            commonElements.push(element);
        }
    }

    return commonElements;
}

// 示例用法
let array1 = [1, 2, 3, 4, 5];
let array2 = [4, 5, 6, 7];
let array3 = [5, 6, 7, 8, 9];

let arrays = [array1, array2, array3];
let commonElements = mergeAndFindCommonArrays(arrays);
console.log(commonElements);