蓝桥杯十六进制转八进制，大数。

#include <cstdio>
#include <algorithm>
#include <cstring>
#include <iostream>
#include <map>
using namespace std;
#define maxn 100100
int main()
{
	int eight[maxn*2];
	char s[maxn];
	char two[maxn*4];
	int n;
	scanf("%d",&n);
	while(n--)
	{
		scanf("%s",s);
		int len = strlen(s);
		int cnt,j;
		memset(eight,sizeof(eight));
		memset(two,'0',sizeof(two));
	//	cout<<two[0]<<endl;
		for(int i=0;i<len;i++)
		{
			if(s[i]>='0'&&s[i]<='9')
			{
				cnt = s[i]-'0';
			}
			else
			{
				cnt = s[i]-'A'+10;
			}
			j = (i+1)*4;
			while(cnt)
			{
				two[j]=cnt%2+'0';
				j--;
				cnt/=2;
			}
		}
		/*for(int i=0;i<len*4;i++)
		cout<<two[i];
		cout<<"--"<<endl;*/
		int t = 0;
		int i;
		for(i=len*4;i-3>=0;i-=3)
		{
			eight[t++]=(two[i]-'0')+(two[i-1]-'0')*2+(two[i-2]-'0')*4;
		}
		cnt = 1;
		if(two[i]!='')
		{
			while(i>0&&two[i]!='')
			{
				eight[t]+=(two[i]-'0')*cnt;
				//cout<<eight[t]<<endl;
				cnt*=2;
				i--;
			}
		}
		t = len*2;
		while(eight[t]==0&&t>=0)t--;
		for(i=t;i>=0;i--)
			printf("%d",eight[i]);
		printf("n");
	}
	return 0;
}