2015百度之星初赛2 1004 魔法因子（暴力+数学）

#include<cstdio>  
#include<cstring>  
#include<cmath>  
#include<cstdlib>  
#include<iostream>  
#include<algorithm>  
#include<vector>  
#include<map>  
#include<queue>  
#include<stack> 
#include<string>
#include<map> 
#include<set>
#define eps 1e-6 
using namespace std;  
#define LL long long  

//const int maxn = ;
const int INF = 0x3f3f3f3f;
//freopen("input.txt", "r", stdin);
const LL po[] = { 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000};


int main() {
	int T, kase = 0; scanf("%d", &T);
	while(T--) {
		double x; cin >> x;
		LL nx = x * 1000000 + 0.5; LL changshu = 1000000; //将浮点数转换为整形 
		vector<LL> ans;
		LL power, firnum, lasnum;
		for(power = 0; power < 9; power++) {
			for(firnum = 1; firnum < 10; firnum++) {
				for(lasnum = 0; lasnum < 10; lasnum++) {
					if((lasnum*(po[power]*changshu-nx)+firnum*(changshu-po[power]*nx)) % (nx-changshu) != 0) continue; 
					LL mid = (lasnum*(po[power]*changshu-nx) + firnum*(changshu-po[power]*nx) )/ (nx-changshu);
					if(mid % 10 != 0) continue;
					if(mid >= po[power] || mid < 0) continue;
					ans.push_back(firnum*po[power] + mid + lasnum);
				}
			}
		} 
		cout << nx << endl;
		printf("Case #%d:\n", ++kase);
		int sz = ans.size();
		if(!sz) puts("0");
		else {
			cout << sz << endl;
			cout << ans[0];
			for(int i = 1; i < sz; i++) cout << " " << ans[i];
			cout << endl;
		}  
	}
	return 0;
}