GUETOJ - 1099 同网CS （模拟检查是否同在内网；ip，子网掩码是否正确）

http://acm.guet.edu.cn/problemset/problem/1099

#include 
#include 
#include 
using namespace std;
const int MAX_N = 101;
int N, M;
struct IP
{
	int ip[4], nm[4];
	
	const bool checkIp()
	{
		if(ip[0] == 127 || ip[0] == 0 || ip[0] == 255) return false;
		for(int i = 0; i < 4; i++)
			if(ip[i] < 0 || ip[i] >255)
				return false;
		return true;
	}
	bool checkNetmask()
	{
		int cnt1 = 0, cnt2 = 0;
		for(int i = 0, flag = 0; i < 4; i++)
		{
			if(nm[i] < 0 || nm[i] >255)
				return false;
			if(nm[i] == 0)
			{
				cnt1++;
				continue;
			}
			else if(nm[i] == 255)
			{
				cnt2++;
				continue;
			}
			int t = nm[i];
			do 
			{
				if(!(t & 1) && flag)
					return false;
				else if(t & 1) 
					flag = 1;
			} while (t = t>>1);
		}
		if(cnt1 == 4 || cnt2 == 4)
			return false;
		return true;
	}
	IP(int t[], int u[])
	{
		for(int i = 0; i < 4; i++) ip[i] = t[i];
		for(int i = 0; i < 4; i++) nm[i] = u[i];
	}
	IP(int t[])
	{
		for(int i = 0; i < 4; i++) ip[i] = t[i];
	}
	bool checkSame(IP ip1)
	{
		for(int i = 0; i < 4; i++)
			if((ip1.ip[i]&nm[i]) != (ip[i]&nm[i]))
				return false;
		return true;
	}
	
};
int getIp(int ip[])
{
	int c;
	if(scanf("%d", ip) == EOF)
		return 0;
	for(int i = 1; i < 4; i++)
		scanf("%c%d", &c, &ip[i]);
	return 1;
}
int main()
{
	//freopen("in.txt", "r", stdin);
	int ip[4], nm[4];
	getIp(ip);
	int f = getIp(nm);
	IP myIp(ip, nm);
	if(!myIp.checkIp())
		printf("Invalid IP address.\n");
	if(!myIp.checkNetmask() && f)
		printf("Invalid netmask address.\n");
	
	scanf("%d", &N);
	while(N--)
	{
		getIp(ip);
		IP ip1(ip);	
		if(!ip1.checkIp())
			printf("Invalid IP address.\n");
		else
		{
			if(myIp.checkSame(ip1))
				printf("let's rock\n");
			else
				printf("not you\n");
		}
	}
	return 0;
}