看到同事桌上有一份面试题，有一个 36 进制运算的题目，手贱敲了一下，不调真的不好做啊

#include <stdio.h>
#include <string>
#include <algorithm>
#include <math.h>

int convert_36_10(std::string strNum) {
	std::reverse(strNum.begin(), strNum.end());
	int n = 0;
	for (int i = 0; i < strNum.size(); i++) {		
		char c = strNum[i];
		if (c >= '0' && c <= '9') {
			n += (c - '0') * pow(36.0, i);
		} else if (c >= 'A' && c <= 'Z') {
			n += (10 + c - 'A') * pow(36.0, i);
		}
	}
	return n * ((strNum[strNum.size() - 1] == '-') ? -1 : 1);
}

std::string convert_10_36(int n) {
	if (n == 0) {
		return "0";
	}
	std::string strNum;
	int s = n > 0;
	n = abs(n);
	while (n) {
		int m = n % 36;
		char c = '-';
		if (m < 10) {
			c = m + '0';
		} else {
			c = m-10 + 'A';
		}
		strNum = c + strNum;
		n /= 36;
	}
	return s ? strNum : "-"+strNum;
}

std::string add(std::string strNum1, std::string strNum2) {
	int n1 = convert_36_10(strNum1);
	int n2 = convert_36_10(strNum2);
	return convert_10_36(n1 + n2);
}

std::string min(std::string strNum1, std::string strNum2) {
	int n1 = convert_36_10(strNum1);
	int n2 = convert_36_10(strNum2);
	return convert_10_36(n1 - n2);
}

int main() {
	while (1) {
		char szNum1[16] = {0}, szNum2[16] = {0};
		scanf("%s%s", szNum1, szNum2);
		printf("%s + %s = %s\n", szNum1, szNum2, add(szNum1, szNum2).c_str());
		printf("%s - %s = %s\n", szNum1, szNum2, min(szNum1, szNum2).c_str());
	}	
	return 0;
}