Uva 389: Basically Speaking

解題心得

先把數字轉回十進位，再轉成要求的進位制表示法。

程式碼

#include <iostream>
using namespace std;

int to_decimal(string s, int base)
{
	int ans = 0;
	for (int i = 0; i < s.size(); i++)
	{
		if ('0' <= s[i] && s[i] <= '9')
			ans = ans * base + s[i] - '0';
		else
			ans = ans * base + s[i] - 'A' + 10;
	}
	return ans;
}
string convert(int n, int base)
{
	string s = "";
	while (n > 0)
	{
		int tmp = n % base;
		if (tmp >= 10)
			s = char(tmp - 10 + 'A') + s;
		else
			s = char(tmp + '0') + s;
		n /= base;
	}
	while (s.size() < 7)
		s = "0" + s;
	while (s.size() > 7)
		s = s.erase(0, 1);
	return s;
}

int main()
{
	string origin;
	int origin_base, new_base;
	while (cin >> origin)
	{
		cin.ignore();
		cin >> origin_base >> new_base;
		int decimal = to_decimal(origin, origin_base);
		cout << convert(decimal, new_base) << endl;
	}
	return 0;
}