题解 | #八进制# 模板无敌了

#include <bits/stdc++.h>

using namespace std;

string convert(string s, int m, int b) {
    string ans; 
    while (!s.empty()) {
        int k = 0; // 余数
        bool leadingZero = true; // 用于去除前导零
        string temp;
        for (int i = 0; i < s.size(); i++) {
        	// 如果是字母字符（用于大于10的进制），则转换为对应的值，如'A' -> 10, 'B' -> 11
            int digit = (isdigit(s[i]) ? s[i] - '0' : s[i] - 'A' + 10);
            int t = (k * m + digit) % b;
            int quotient = (k * m + digit) / b;
            k = t;
            if (quotient != 0 || !leadingZero) {
                temp += (quotient < 10 ? quotient + '0' : quotient - 10 + 'A');
                leadingZero = false;
            }
        }
        ans += (k < 10 ? k + '0' : k - 10 + 'A');
        s = temp;
    }
    reverse(ans.begin(), ans.end());
    return ans.empty() ? "0" : ans;
}

int main(){
	string s;
	
	while(cin >> s){
		string answer = convert(s,10,8);	
		cout << answer << endl;
	}
	
	return 0;
}