基础数学问题 P1143 进制转换

题目

https://www.luogu.com.cn/problem/P1143

代码

#include<iostream>
#include<cmath>
#include<string>
#include<cstring>
using  namespace std;
int main()
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    std::cout.tie(0);
    int n, m;
    string tmp;
    long long num = 0;
    cin >> n >> tmp >> m;
    for (int i = 0; i < tmp.length(); i++)
    {
        if (isupper(tmp[i]))num = num + (tmp[i] - 'A' + 10)*pow(n, tmp.length() - i - 1);
        if(isdigit(tmp[i]))num=num+(tmp[i]-'0')*pow(n, tmp.length() - i - 1);
    }
    int list[50000];
    int cnt = 0;
    while (num)
    {
        list[cnt++] = num % m;
        num /= m;
    }
    for (int i = cnt-1; i >=0; i--)//注意这里的顺序
    {
        if (list[i] < 10)
            cout << list[i];
        else
            cout << (char)(list[i] - 10 + 'A');
    }

}