yuvalAmaniuk2

#include <iostream>
#include <cmath>

bool solution(int *arr, int size);
bool checkIfPossibleToGenEditedNumberBiggerThanLeftSmallerThanRightBySwappingTwoDigits(int *arr, int size,
                                                                                       int leftToEditedNumberIdx, int editedNumberIdx, int rightToEditedNumberIdx);
int generateNewNumberBySwappingTwoDigits(int number, int chosenDigitToSwapFromRight, int chosenDigitToSwapWithFromRight);
int pow(int num, int toPower);

int main()
{
   int arr[] = {13, 31, 30};
   int size = sizeof(arr) / sizeof(*arr);
   std::cout << solution(arr, size) << std::endl;
}

bool solution(int *arr, int size)
{
   int counterOfBreaksToMakeArrayAscending = 0;
   for (int i = 1; i < size; ++i)
   {
      if (arr[i] <= arr[i - 1])
         ++counterOfBreaksToMakeArrayAscending;
   }
   // Three Cases:
   // Case A: it's already ascending array
   if (counterOfBreaksToMakeArrayAscending == 0)
      return true;
   // Case B: There has to be more than one swaps [between number digits] to make it happen, if it even could
   if (counterOfBreaksToMakeArrayAscending > 1)
      return false;

   // Case C: That's MAYBE possible - we need to find the three numbers that are making it happen and make sure it can be done
   int leftToEditedNumberIdx = -1;
   int editedNumberIdx = -1;
   int rightToEditedNumberIdx = -1;

   for (int i = 0; i < size; ++i)
   {
      // left side of the condition will happen for sure only when the x y z are [...,x,y,]z
      if (i < size - 1 && arr[i] >= arr[i + 1])
      {
         leftToEditedNumberIdx = i - 1;
         editedNumberIdx = i;
         rightToEditedNumberIdx = i + 1;
         break;
      }
   }
   return checkIfPossibleToGenEditedNumberBiggerThanLeftSmallerThanRightBySwappingTwoDigits(arr, size,
                                                                                            leftToEditedNumberIdx,
                                                                                            editedNumberIdx,
                                                                                            rightToEditedNumberIdx);
}

bool checkIfPossibleToGenEditedNumberBiggerThanLeftSmallerThanRightBySwappingTwoDigits(int *arr, int size,
                                                                                       int leftToEditedNumberIdx, int editedNumberIdx, int rightToEditedNumberIdx)
{
   int lengthOfNumber = log10(arr[editedNumberIdx]);
   int numToEdit = arr[editedNumberIdx];
   int leftNumber = leftToEditedNumberIdx != -1 ? arr[leftToEditedNumberIdx] : INT_MIN;
   int rightNumber = rightToEditedNumberIdx != size ? arr[rightToEditedNumberIdx] : INT_MAX;

   int editedNumber = -1;
   for (int i = 0; i <= lengthOfNumber; ++i)
   {
      for (int j = 0; j <= lengthOfNumber; ++j)
      {
         if (i != j)
         {
            int editedNumber = generateNewNumberBySwappingTwoDigits(numToEdit, i, j);

            if (editedNumber > leftNumber && editedNumber < rightNumber)
               return true;
         }
      }
   }
   return false;
}

// chosenDigitToSwapFromRight - idx from right to left that represents what digit we will replace with some other

// firstDigit = (num / 10^chosenIdx1) % 10; = 0 -> extracting the digit
// secondDigit = (num / 10^chosenIdx2) % 10; = 6 -> extracting the second digit

int generateNewNumberBySwappingTwoDigits(int number, int chosenDigitToSwapFromRight, int chosenDigitToSwapWithFromRight)
{
   int firstDigit = (number / pow(10, chosenDigitToSwapFromRight)) % 10;
   int secondDigit = (number / pow(10, chosenDigitToSwapWithFromRight)) % 10;
   int builtNumber = 0;
   int digIdx = 0;
   int tens = 1;

   while (number != 0)
   {
      if (digIdx == chosenDigitToSwapFromRight)
      {
         builtNumber = builtNumber + secondDigit * tens;
      }
      else if (digIdx == chosenDigitToSwapWithFromRight)
      {
         builtNumber = builtNumber + firstDigit * tens;
      }
      else
      {
         builtNumber = builtNumber + (number % 10) * tens;
      }

      tens *= 10;
      number /= 10;
      ++digIdx;
   }
   return builtNumber;
}

int pow(int num, int toPower)
{
   if (toPower == 0)
      return 1;
   return pow(num, toPower - 1) * num;
}