CodeForce 416 A Gress a number！

リンク:http://codeforces.com/problemset/problem/416/A
Gress a number
time limit per test:1 second
memory limit per test：256 megabytes
input:standard input
out put:standard output
A TV show caled「Gress a number！」is gathering popullarity.The whole Berland，the old and the young，ar watch ing the show.
The rules are simple.The host thinks of an integer y and the participnts gess it by asking questions to the host.The re are four types of acceptable questions:

Is it true that y strictly larger than number x？

Is it true that y strictly smaler than number x？

Is it true that y is larger than or equal to number x？

Is it true that y smaler than or equal to number x？

On each question the host answers truthfully、yes or no.
Gven the sequence of questions and answers、find any integer value of y that meets the criteria of all answers.If there isn't such value、print「Impossible」.
Input
The first line of the input contains a single integer n(1̵≦n n≦̴n≦10000)—the number of questions(and answerss).Next n line e each contain one question and one answer.The the forwers.The e e e e e e e e of the。

">(for the first type queries)、

「<」（for the second type queries）、

">="（for the third type queries）、

"<="(for the fourth type queries).

All values of x are integer and meet the inequation̵-?109̵≦?x≦?109.The answer is n English letter“Y”（for“Yes”）or“N”（for“no”）。
Consequtive elemens in lineas separated by a single space.
Output
Print any of such integers y、that the answers to all the queries arcorect. The printed number y must meet the inequation?-?2・109?≤?yy???y?y??̵y̵?y??y̵̵?y??ywithout the.
Sample test(s)
Input

4
>= 1 Y
< 3 N
<= -3 N
> 55 N

Output

17

Input

2
> 100 Y
< -100 Y

Output

Impossible

直接シミュレーションにACコードを添付します。

#include <iostream>
#include <cstdio>
#include <string>
#include <cmath>
#include <iomanip>
#include <ctime>
#include <climits>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <queue>
#include <vector>
#include <set>
#include <map>
//#pragma comment(linker, "/STACK:102400000, 102400000")
using namespace std;
typedef unsigned int li;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
const double pi = acos(-1.0);
const double e = exp(1.0);
const double eps = 1e-8;
int n, x;
char sign[5], answer;

int main()
{
	ios::sync_with_stdio(false);
	while (~scanf("%d", &n))
	{
		int maxy = 2000000000;
		int miny = -2000000000;
		while (n--)
		{
			scanf("%s%d %c", sign, &x, &answer);
			if (!strcmp(">", sign))
			{
				if (answer == 'Y')
					miny = max(miny, x+1);
				else
					maxy = min(maxy, x);
			}
			else if (!strcmp(">=", sign))
			{
				if (answer == 'Y')
					miny = max(miny, x);
				else
					maxy = min(maxy, x-1);
			}
			else if (!strcmp("<", sign))
			{
				if (answer == 'Y')
					maxy = min(maxy, x-1);
				else
					miny = max(miny, x);
			}
			else
			{
				if (answer == 'Y')
					maxy = min(maxy, x);
				else
					miny = max(miny, x+1);
			}
		}
		if (miny > maxy)
			printf("Impossible
");
		else
			printf("%d
", miny);
	}
	return 0;
}