Write a function that converts the binary number to the decimal number. For example "10" in binary will be "2" in decimal.

Question

Input:
First line contains N(1<=N<=31). That N symbols are inputed(all are 0 or 1)
Output:
The number in decimal format

Input Output
4 9
1001

How to write numbers without space between them?

#include <iostream>
#include <cmath>

using namespace std;

int convert(char arr[31],int n)
{
double decimalNumber = 0, remainder;
for (int i = 0; i < n; i++) {
while (arr[i] != 0)
{
remainder = arr[i] % 10;
arr[i] /= 10;
decimalNumber += remainder * pow(2, i);
++i;
}
}

return decimalNumber;
}

int main()
{
int n;
cin >> n;
char arr[31];
for (int i = 0; i < n; i++) {
cin >> arr[i];
}

cout << convert(arr,n) ;
return 0;
}