codevs1475m进制转10进制

#include <iostream>
#include <string>
#include <math.h>
using namespace std;
string n;
int m;
int sum=0;

int main()
{
	cin >> n >> m;
	for (int i = 0; i < n.length(); ++i)
	{
		if (n[i] <= '9')
			sum += pow(m, n.length() - 1 - i)*(n[i] - 48);
		else
			sum += pow(m, n.length() - 1 - i)*(n[i] - 55);
	}
	cout << sum;
	return 0;
}