Kertoma

#include <iostream>
#include <cmath>
#include <string>
#include <bits/stdc++.h>
using namespace std;

long int * getDigits(long int x) {
  static long int digits[10];
  for (int i = 0; i < 10; i++) {
    digits[i] = 0;
  }

  string str = to_string(x);
  for (long unsigned int i = 0; i < str.length(); i++) {
    digits[stoi(str.substr(i,1))]++;
  }
  return digits;
}

bool checkNum(long int x, int * digits) {
  long int * d = getDigits(x);
  for (int i = 0; i < 10; i++) {
    if (digits[i] != d[i]) {
      return false;
    }
  }
  return true;
}

bool calcSubTen(int * digits) {
  int r = 1;
  for (int i = 2; i < 10; i++) {
    r *= i;
    if (checkNum(r, digits)) {
      cout << i;
      return true;
    }
  }
  return false;
}

int main() {

  int digits[10];
  int digitCount = 0;
  for (int i = 0; i < 10; i++) {
    cin >> digits[i];
    digitCount += digits[i];
  }

  if (calcSubTen(digits)) {
    return 0;
  }

  double value = 1;
  long i = 1;
  while (true) {
    double m = log10(i);
    value += m;
    if (value > digitCount) {
      cout << i;
      break;
    }
    i++;
  } 
  
  return 0;
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 1, 2, 3

Verdict: ACCEPTED

Test 3

Group: 1, 2, 3

Verdict: ACCEPTED

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED

Test 6

Group: 1, 2, 3

Verdict: ACCEPTED

Test 7

Group: 2, 3

Verdict: ACCEPTED

Test 8

Group: 2, 3

Verdict: ACCEPTED

Test 9

Group: 2, 3

Verdict: ACCEPTED

Test 10

Group: 2, 3

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED

Test 16

Group: 3

Verdict: ACCEPTED