题解 | #进制转换#
进制转换
https://www.nowcoder.com/practice/8f3df50d2b9043208c5eed283d1d4da6
递归实现数值转换
可以适当修改实现结果为32位以内的任何数值转换
#include<iostream>
using namespace std;
int quickpower(int a,int n){
int ans=1;
while(n){
if(n&1)ans*=a;
a*=a;
n=n>>1;
}
return ans;
}
int fun(string s,int idx){
if(idx==s.size()-1){
char c=s[idx];
if(c>='A'&&c<='Z')c=tolower(c);
int temp= c>='0'&&c<='9' ?c-'0':(c-'a'+10);
return quickpower(16, s.size()-1-idx)*temp;
}
char c=s[idx];
if(c>='A'&&c<='Z')c=tolower(c);
int temp= c>='0'&&c<='9' ?c-'0':(c-'a'+10);
return quickpower(16, s.size()-1-idx)*temp+fun(s,idx+1);
}
int main(){
string s;
while(cin>>s)
cout<<fun(s.substr(2,s.size()-2),0)<<endl;
}
