fullSort.js

function permutate(str) {
  //保存每一轮递归的排列结果
  var result = [];
  //初始条件：长度为1
  if (str.length == 1) {
      return [str]
  } else {
      //求剩余子串的全排列,对每个排列进行遍历
      var preResult = permutate(str.slice(1));
      for (var j = 0; j < preResult.length; j++) {
          for (var k = 0; k < preResult[j].length + 1; k++) {
              //将首字母插入k位置  
              console.log(preResult)
              var temp = preResult[j].slice(0, k) + str[0] + preResult[j].slice(k);
              result.push(temp);
          }
      }
      return result;
  }
}

console.log(permutate('abc'));


function test (str) {
  let arr = [];
  if (str.length == 1) {
    return [str];
  } else {
    let str2 = test(str.slice(1));
    for (let i = 0; i < str2.length; i++) {
      let item = str2[i]
      for (let j = 0; j < item.length + 1; j++) {
        let temp = item.slice(0, j) + str[0] + item.slice(j);
        arr.push(temp)
      }
    }
    return arr;
  }
}

console.log(test('abc'))