1010. Radix (25)

Given a pair of positive integers, for example, 6 and 110, can this equation 6 = 110 be true? The answer is "yes", if 6 is a decimal number and 110 is a binary number.

Now for any pair of positive integers N1 and N2, your task is to find the radix of one number while that of the other is given.

Input Specification:

Each input file contains one test case. Each case occupies a line which contains 4 positive integers:
N1 N2 tag radix
Here N1 and N2 each has no more than 10 digits. A digit is less than its radix and is chosen from the set {0-9, a-z} where 0-9 represent the decimal numbers 0-9, and a-z represent the decimal numbers 10-35. The last number "radix" is the radix of N1 if "tag" is 1, or of N2 if "tag" is 2.

Output Specification:

For each test case, print in one line the radix of the other number so that the equation N1 = N2 is true. If the equation is impossible, print "Impossible". If the solution is not unique, output the smallest possible radix.

Sample Input 1:

6 110 1 10

Sample Output 1:

2

Sample Input 2:

1 ab 1 2

Sample Output 2:

Impossible

暴力破解，只得了22分，已知足了，只可惜是个半成品！！！复试之后再写吧。。

#include <iostream>
#include <map>
#include <queue>
#include <stdio.h>
#include <vector>
#include <algorithm>
#include <stack>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <string>
using namespace std;

int p1(char *p,int radix)  
{  	  
	int len=strlen(p);  
	int digit = 0;  
	int m = 1;  
	int sum = 0;  
	for(int i=len-1;i>=0;i--)  
	{  
		if(p[i]>='a'&&p[i]<='z') { 
			digit= p[i] - 'a' + 10;
			if(digit>=radix)
				break;
		}
		else if(p[i]>='0'&& p[i]<='9'){  
			digit=p[i] - '0'; 
			if(digit>=radix)
				break ;
		}
		sum+=digit*m;  
		m*=radix;
	}  
	return sum;  
}
int max(int x,int y){
	return x<y?y:x;
}
int main(){
	int n,m,p,q;
	char c1[10],c2[10];
	scanf("%s%s%d%d",c1,c2,&p,&q);
	int flag=0;
	int l1=strlen(c1);
	int l2=strlen(c2);
	int l=max(l1,l2);

	if(p==1){
		int i;
		int n1=p1(c1,q);
		for(i=1;i<10000;i++){
			//int n2=p1(c2,i);
			if(n1==p1(c2,i)){
				cout<<i<<endl;
				break;
			}
		}
		if(i==10000)
			cout<<"Impossible"<<endl;
	}else{
		int n1=p1(c2,q);
		int i;
		for(i=1;i<10000;i++){
			int n2=p1(c1,i);
			if(n1==n2){
				cout<<i<<endl;
				break;
			}
		}
		if(i==10000)
			cout<<"Impossible"<<endl;
	}
	return 0;
}