基础练习 十六进制转十进制

#include<iostream>#include<string>#include<cstring>#include<algorithm>using namespace std;//将N进制转成十进制long long  TransFromN(string data,int n){    long long  i,y,j,a[50];    long long result=0;     int length=data.length();	for(i=0;i<length;i++)	{		if(data[i]>='0' && data[i]<='9')			a[i]=data[i]-'0';		else			a[i]=toupper(data[i])-'A'+10;	}	long long power=0;	for(i=length-1;i>=0;i--)	{		y=1;		for(j=1;j<=power;j++)			y=y*n;		power++;		result+=y*a[i];	}	return result;}int main(){	string data;	int n=16;	while(cin>>data)	{		long long result=TransFromN(data,16);		cout<<result<<endl;	}	return 0;}