{POJ}{3989}{A hard Aoshu Problem}{DFS}

10年福州赛区的题目，暴力搜索即可。

#include <iostream>
#include <string>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <memory>
#include <cmath>
#include <bitset>
#include <queue>
#include <vector>
#include <stack>
using namespace std;

#define CLR(x,y) memset(x,y,sizeof(x))
#define MIN(m,v) (m)<(v)?(m):(v)
#define MAX(m,v) (m)>(v)?(m):(v)
#define ABS(x) ((x)>0?(x):-(x))
#define rep(i,x,y) for(i=x;i<y;++i)

char s1[10],s2[10],s3[10];
char dir[10];
bool bd[300];
int bk[300];
bool vb[100];
long long a,b,c;
int len1,len2,len3;
int ans;
int kk;
int init()
{
	return 0;
}
int ai( char* str, int len)
{
	int i,tmp = 0;
	if( bk[str[0]] == 0 && len > 1)
		return -1;
	rep(i,0,len)
		tmp = tmp * 10 + bk[str[i]];
	return tmp;
}

int dfs(int k)
{
	if(k == kk) {
		a = ai(s1,len1);
		b = ai(s2,len2);
		c = ai(s3,len3);
		if( a != -1 && b != -1 && c != -1) {
			//printf("[%lld %lld %lld]",a,b,c);
			if( a + b - c == 0) ++ans;
			if( a - b - c == 0) ++ans;
			if( a * b - c == 0) ++ans;
			if( a - b * c == 0 && b != 0) ++ans;
		}
		return 0;
	}
	for( int i = 0; i < 10; ++i) {
		if( vb[i] )
			continue;
		bk[dir[k]] = i;
		vb[i] = true;
		dfs(k+1);
		vb[i] = false;
	}
	return 0;
}
int work()
{
	int cnt;
	int i;
	scanf("%d",&cnt);
	while( cnt -- ){
		CLR(vb,0);
		CLR(bd,0);
		cin>>s1>>s2>>s3;
		len1 = strlen(s1);
		rep(i,0,len1)
			bd[s1[i]] = true;
		len2 = strlen(s2);
		rep(i,0,len2)
			bd[s2[i]] = true;
		len3 = strlen(s3);
		rep(i,0,len3)
			bd[s3[i]] = true;
		kk = 0;
		if( bd['A'] ) {
			dir[kk] = 'A';
			++kk;
		}
		if ( bd['B']) {
			dir[kk] = 'B';
			++kk;
		}
		if ( bd['C']) {
			dir[kk] = 'C';
			++kk;
		}
		if ( bd['D']) {
			dir[kk] = 'D';
			++kk;
		}
		if ( bd['E']) {
			dir[kk] = 'E';
			++kk;
		}
		ans = 0;
		dfs(0);
		printf("%d\n",ans);
	}
	return 0;
}
int main()
{
	init();
	work();
	return 0;
}