"对函数进行更改，该函数将序列作为参数并返回一个项目列表，其中没有任何具有相同值的元素"

Question

Implement the function unique_in_order which takes as argument a sequence and returns a list of items without any elements with the same value next to each other and preserving the original order of elements. For example:

uniqueInOrder('AAAABBBCCDAABBB') == ['A', 'B', 'C', 'D', 'A', 'B']

 var uniqueInOrder = function(it) { let n = 0; let arr = []; let i = 0; let m = 0; length = it.length; if (length == 0) { return arr } else { if (n == 0) { arr.push(it[0]); n += 1; } while (n < length) { if (arr[i] != it[m + 1]) { arr.push(it[m + 1]) i += 1; n += 1 } else { m += 1 n += 1 } } return arr } } console.log(uniqueInOrder('AAAABBBCCDAABBB'));

should reduce duplicates:

Expected: '[\\'A\\', \\'B\\', \\'C\\', \\'D\\', \\'A\\', \\'B\\']'

instead got : '[\\'A\\', \\'B\\', \\'C\\', \\'D\\', \\'A\\']'

should treat lowercase as different from uppercase:

Expected: '[\\'A\\', \\'B\\', \\'C\\', \\'c\\', \\'A\\', \\'D\\']'

instead got : '[\\'A\\', \\'B\\', \\'C\\', \\'c\\']'

Answer 1

You need to increase m at each iteration not just when a match is not found. The same goes for n

 var uniqueInOrder = function(it) { let n = 0; let arr = []; let i = 0; let m = 0; length = it.length; if (length == 0) { return arr } else { if (n == 0) { arr.push(it[0]); n += 1; } while (n < length) { if (arr[i] != it[m + 1]) { arr.push(it[m + 1]) i += 1; n += 1 } m += 1 n += 1 } return arr } } console.log(uniqueInOrder('AAAABBBCCDAABBB'));

Answer 2

you can do this :

 var uniqueInOrder = function(it){ var arr = it.split('') var newArr = [] arr.forEach((char,idx) => { if ( idx !== arr.length && char !== arr[idx+1]) newArr.push(char) }) return newArr }

Answer 3

The Solution can be implemented using

• Using rest & spread operator
• Checking if the input is a string or an array

Below is the working code

  var uniqueInOrder=function(iterable){
  if (typeof iterable === 'string') {
            let newArray = [];
            const [...arr] = [...iterable];
            for (let i = 0; i < arr.length; i++) {
                if (arr[i] != arr[i + 1]) {
                    newArray.push(arr[i])
                }
            }
             return newArray;
          }
  else{
    let newArray = [];
    for (let i = 0; i < iterable.length; i++) {
                if (iterable[i] != iterable[i + 1]) {
                    newArray.push(arr[i])
                }
            }
             return newArray;
  }
}