题解 | 16进制加法

#include <bits/stdc++.h>
using namespace std;
char c[16]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};//十六进制数组
int f(char ch){//转换
    if(ch>='0'&&ch<='9')return ch-'0';
    if(ch>='A'&&ch<='F')return ch-'A'+10;
    return 0;
}
int main() {
    string a,b;
    cin>>a>>b;
    long long ra=0;
    for (int i=2;i<a.size();i++) {
        ra=ra*16+f(a[i]);
    }//a求值
    long long rb=0;
    for (int i=2;i<b.size();i++){
        rb=rb*16+f(b[i]);
    }//b求值
    long long t=ra+rb;
    if(t==0){
        cout<<"0X0"<<endl;
        return 0;
    }//特殊判断
    string ul="";
    while(t>0){
        ul+=c[t%16];//转换为十六进制
        t/=16;
    }
    reverse(ul.begin(),ul.end());//根据特性翻转字符串
    cout<<"0X"<<ul;
}