题解 | #进制转换2#

#include<iostream>
#include<cstdio>
#include<stack>

using namespace std;

int CharToInt(char c){
	if(c >= '0' && c <= '9'){
		return c - '0';        //数字型字符转数字
	}else{
		return c - 'A' + 10;   //字符型字符转数字
	}
}


char IntToChar(int target){
	if(target < 10){
		return target + '0';        
	}else{
		return target + 'a' - 10;   
	}
}

long long  ConvertM2T(string str,int current){      //current为当前需转换的目标的当前进制
	long long  number = 0;
	for(int i = 0; i < str.size(); ++i){
		number *= current;
		number += CharToInt(str[i]);
	}
	return number;
}

void ConvertT2N(long long  number,int target) {   //target为目标进制
	stack<char> myStack;
	if(number == 0){
		myStack.push('0');
	}
	while(number != 0) {
		myStack.push(IntToChar(number % target));
		number /= target;
	}
	while(!myStack.empty()) {
		printf("%c",myStack.top());
		myStack.pop();
	}
	printf("\n");
}


int main() {
	int m,n;
	while(scanf("%d%d",&m,&n) != EOF){
		string str;
		cin >> str;
		long long number = ConvertM2T(str,m);    //先转换成十进制
		ConvertT2N(number,n);     //再将十进制转n进制
	}
	return 0;
}