Hifipsysta-2080-蓝桥杯基础练习-十六进制转八进制（C++代码）

#include<iostream>
#include<cmath>
#include<algorithm>
#include<vector>
using namespace std;
long long M2Ten(string mystr, int M){
    long long num, sum = 0;
    for(int i=0;i<mystr.size();i++){
        if(mystr[i]>='0' && mystr[i]<='9'){
            num = mystr[i] - '0';
        }
        else{
            num = mystr[i] - 'A' + 10;
        }
        sum += num * pow(M, i);
    }
    return sum;
}
vector<int> Ten2N(long long number, int N){
    vector<int> vect;
    if(number<N){
        vect.push_back(number);
    }
    else{
        while(number != 0){
            vect.push_back(number%N);
            number /= N;
        }
    }
    reverse(vect.begin(), vect.end());
    return vect;
}
int main(){
    string tmp;
    int N;
    long long number;
    vector<int> myvect;
    cin>>N;
    for(int i=0;i<N;i++){
        cin>>tmp;
        reverse(tmp.begin(),tmp.end());
        number = M2Ten(tmp, 16);
        myvect = Ten2N(number, 8);
        for(int j=0; j<myvect.size(); j++){
            cout<<myvect[j];
        }
        cout<<endl;
    }
    return 0;
}