集训营的题解

#include<iostream>
#include<map>
#include<math.h>
#include<algorithm>
using namespace std;

map<int,char> mp;
void init(){
    for (char i='0';i<='9';i++) mp[i-'0']=i;
    for (char i='A';i<='Z';i++) mp[i-55]=i;
}
string binaryToDecimal(const string& binary) {
    long long decimal = 0;
    int length = binary.length();
    
    for (int i = 0; i < length; i++) {
        int power = length - 1 - i;
        decimal += (binary[i] - '0') * pow(2, power);
    }
    return to_string(decimal);
}
string tenq(int n,int q) {
    string s;
    do{
        int r=n%q;
        n/=q;
        s+=mp[r];
    }while(n);
    reverse(s.begin(),s.end());
    return s;
}
int main(){
    init();
    string bin;
    int x;
    cin>>bin>>x;
    string dec=binaryToDecimal(bin);
    cout<<tenq(stoll(dec),x);
    return 0;
}