问题 B: 数制转换

1.对于多点测试必须EOF

2.输入0~F需要分类讨论

#include<cstdio>
#include<string.h>
#include<iostream>
using namespace std;
int main(){
    char x[100];
    int p;
    int p2;//48
    while(scanf("%d%s %d",&p,x,&p2)){

    int product=1;
    long y=0;
    int n = strlen(x);
   // printf("%d  ",n);
    for(int i=n-1;i>=0;i--){
        if(x[i]<58&&x[i]>=48)x[i]-='0';
    else if(x[i]>=65&&x[i]<80)x[i]-=55;
    else  x[i]-=87;

        y=y+(x[i])*product;
        product *=p;
    }
    //printf("%ld",y);

    char z[80],num=0;
   do{
        if(y%p2<10){
            z[num++]=y%p2+48;
        }else
       z[num++]=y%p2+55;

        y/=p2;
    }while(y!=0);
    for(int i=num-1;i>=0;i--){
        printf("%c",z[i]);
    }
printf("\n");
    }
    return 0;
}