Access control 21.08.13

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

map<long long, char> m;

long long ip(long long a, long long b, long long c, long long d) {
        long long r = 0;
        r |= (a << 24);
        r |= (b << 16);
        r |= (c << 8);
        r |= d;
        return r;
}

char z[100010][50];
int n, k, a, b, c, d, q;
long long x[100010], y;

set<long long> ips;

int main() {
        freopen("access.in", "r", stdin);
        freopen("access.out", "w", stdout);

        scanf("%d\n", &n);
        for (int i = 0; i < n; i++)
                gets(z[i]);
        scanf("%d", &k);
        for (int i = 0; i < k; i++) {
                scanf("%d.%d.%d.%d", &a, &b, &c, &d);
                x[i] = ip(a, b, c, d);
                ips.insert(x[i]);
        }

        for (int i = 0; i < n; i++) {
                char mode = z[i][0] == 'a' ? 'A' : 'D';
                sscanf(z[i], "%*s%*s%d.%d.%d.%d", &a, &b, &c, &d);
                long long net = ip(a, b, c, d);
                long long net2 = 0;
                if (strchr(z[i], '/')) {
                        sscanf(z[i], "%*s%*s%*d.%*d.%*d.%*d/%d", &q);
                        q = 32 - q;
                        long long mask = 1;
                        mask = (mask << 32) - 1;
                        mask = (mask << q) & mask;
                        net &= mask;
                        net2 = 1;
                        net2 <<= q;
                        net2--;
                }
        set<long long>::iterator first = ips.lower_bound(net), f = first;
        set<long long>::iterator last  = ips.upper_bound(net + net2);
        for( ; f != last; ++f) {
            m.insert(make_pair(*f, mode));
        }
        ips.erase(first, last);
        }

        for (int i = 0; i < k; i++) {
                printf("%c", m.find(x[i]) == m.end() ? 'A' : m[x[i]]);
        }

        return 0;
}