Javascript - 计算没有重复数字的数字 -- leetcode 1012. 有重复数字的数字

Question

https://leetcode.com/problems/numbers-with-repeated-digits/

Given a positive integer N, return the number of positive integers less than or equal to N that have at least 1 repeated digit.

Example 1:

Input: 20 Output: 1 Explanation: The only positive number (<= 20) with at least 1 repeated digit is 11. Example 2:

Input: 100 Output: 10 Explanation: The positive numbers (<= 100) with atleast 1 repeated digit are 11, 22, 33, 44, 55, 66, 77, 88, 99, and 100. Example 3:

Input: 1000 Output: 262

Note:

1 <= N <= 10^9

https://leetcode.com/problems/numbers-with-repeated-digits/discuss/256725/JavaPython-Count-the-Number-Without-Repeated-Digit I found out this solution has many likes. but it's coded in Java/Python. Anyone can help to use Javascript to code it by the similar logic. Really appreciate...

python solution: I have no clue how the set() part, how to use Javascript to do it.

def numDupDigitsAtMostN(self, N): L = map(int, str(N + 1)) res, n = 0, len(L)

    def A(m, n):
        return 1 if n == 0 else A(m, n - 1) * (m - n + 1)

    for i in range(1, n): res += 9 * A(9, i - 1)
    s = set()
    for i, x in enumerate(L):
        for y in range(0 if i else 1, x):
            if y not in s:
                res += A(9 - i, n - i - 1)
        if x in s: break
        s.add(x)
    return N - res

Answer 1

While I can't translate the python, I think what you need to do is break the integer to array of char, so 100 would become ["1","0","0"], and do a comparison from the 1st element (array[0]) to the last element to see if any of the char is the same.

Here is a quick function that I do.. maybe it will run slower than the python, but it should do the job:

var result = [];
function x(n) {
  for (var i = 0; i <= n; i++){
    var nStr = i.toString();
    var nStrArr = nStr.split('');
    if(nStrArr.length > 1){
      for(var j = 0; j < nStrArr.length; j++){
        var idx = nStrArr.findIndex(x => x === nStrArr[j]);
        if(idx >= 0 && idx !== j){
          result.push(parseInt(i));
          break;
        }
      }
    }
  }
  console.log(result); //should list all the numbers with at least 1 repeated digit
  console.log(result.length); //length of the array
}

x(1000);