// 多个数组进行组合
let Combination = {
  recursion(array, depth) {
    for (var i = 0; i < array[depth].length; i++) {
      this.result[depth] = array[depth][i];
      if (depth != array.length - 1) {
        this.recursion(array, depth + 1);
      } else {
        this.results.push([...this.result]);
      }
    }
  },
  begin(array) {
    this.results = [];
    this.result = [];
    this.recursion(array, 0);
    return this.results;
  }
};