UVA 1590 IP Networks

  1 #include <bits/stdc++.h>
  2 using namespace std;
  3  
  4 #define INIT() ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
  5 #define Rep(i,n) for (int i = 0; i < (n); ++i)
  6 #define For(i,s,t) for (int i = (s); i <= (t); ++i)
  7 #define rFor(i,t,s) for (int i = (t); i >= (s); --i)
  8 #define ForLL(i, s, t) for (LL i = LL(s); i <= LL(t); ++i)
  9 #define rForLL(i, t, s) for (LL i = LL(t); i >= LL(s); --i)
 10 #define foreach(i,c) for (__typeof(c.begin()) i = c.begin(); i != c.end(); ++i)
 11 #define rforeach(i,c) for (__typeof(c.rbegin()) i = c.rbegin(); i != c.rend(); ++i)
 12  
 13 #define pr(x) cout << #x << " = " << x << "  "
 14 #define prln(x) cout << #x << " = " << x << endl
 15  
 16 #define LOWBIT(x) ((x)&(-x))
 17  
 18 #define ALL(x) x.begin(),x.end()
 19 #define INS(x) inserter(x,x.begin())
 20  
 21 #define ms0(a) memset(a,0,sizeof(a))
 22 #define msI(a) memset(a,inf,sizeof(a))
 23 #define msM(a) memset(a,-1,sizeof(a))
 24 
 25 #define MP make_pair
 26 #define PB push_back
 27 #define ft first
 28 #define sd second
 29  
 30 template<typename T1, typename T2>
 31 istream &operator>>(istream &in, pair<T1, T2> &p) {
 32     in >> p.first >> p.second;
 33     return in;
 34 }
 35  
 36 template<typename T>
 37 istream &operator>>(istream &in, vector<T> &v) {
 38     for (auto &x: v)
 39         in >> x;
 40     return in;
 41 }
 42  
 43 template<typename T1, typename T2>
 44 ostream &operator<<(ostream &out, const std::pair<T1, T2> &p) {
 45     out << "[" << p.first << ", " << p.second << "]" << "\n";
 46     return out;
 47 }
 48 
 49 inline int gc(){
 50     static const int BUF = 1e7;
 51     static char buf[BUF], *bg = buf + BUF, *ed = bg;
 52     
 53     if(bg == ed) fread(bg = buf, 1, BUF, stdin);
 54     return *bg++;
 55 } 
 56 
 57 inline int ri(){
 58     int x = 0, f = 1, c = gc();
 59     for(; c<48||c>57; f = c==‘-‘?-1:f, c=gc());
 60     for(; c>47&&c<58; x = x*10 + c - 48, c=gc());
 61     return x*f;
 62 }
 63 
 64 template<class T>
 65 inline string toString(T x) {
 66     ostringstream sout;
 67     sout << x;
 68     return sout.str();
 69 }
 70  
 71 typedef long long LL;
 72 typedef unsigned long long uLL;
 73 typedef pair< double, double > PDD;
 74 typedef pair< int, int > PII;
 75 typedef pair< int, PII > PIPII;
 76 typedef pair< string, int > PSI;
 77 typedef pair< int, PSI > PIPSI;
 78 typedef set< int > SI;
 79 typedef set< PII > SPII;
 80 typedef vector< int > VI;
 81 typedef vector< VI > VVI;
 82 typedef vector< PII > VPII;
 83 typedef map< int, int > MII;
 84 typedef map< int, string > MIS;
 85 typedef map< int, PII > MIPII;
 86 typedef map< PII, int > MPIII;
 87 typedef map< string, int > MSI;
 88 typedef map< string, string > MSS;
 89 typedef map< PII, string > MPIIS;
 90 typedef map< PII, PII > MPIIPII;
 91 typedef multimap< int, int > MMII;
 92 typedef multimap< string, int > MMSI;
 93 //typedef unordered_map< int, int > uMII;
 94 typedef pair< LL, LL > PLL;
 95 typedef vector< LL > VL;
 96 typedef vector< VL > VVL;
 97 typedef priority_queue< int > PQIMax;
 98 typedef priority_queue< int, VI, greater< int > > PQIMin;
 99 const double EPS = 1e-6;
100 const LL inf = 0x7fffffff;
101 const LL infLL = 0x7fffffffffffffffLL;
102 const LL mod = 1e9 + 7;
103 const int maxN = 1e3 + 7;
104 const LL ONE = 1;
105 const LL evenBits = 0xaaaaaaaaaaaaaaaa;
106 const LL oddBits = 0x5555555555555555;
107 
108 struct IP{
109     int ip[4] = {0};
110     
111     void allone() {
112         Rep(i, 4) ip[i] = 255;
113     }
114     
115     void allzero() {
116         Rep(i, 4) ip[i] = 0;
117     }
118     
119     void removeLowbit() {
120         rFor(i, 3, 0) {
121             if(ip[i] == 0) continue;
122             ip[i] &= ip[i] - 1;
123             break;
124         }
125     }
126     
127     bool isZero() {
128         Rep(i, 4) if(ip[i]) return false;
129         return true;
130     }
131     
132     bool operator< (const IP &x) const {
133         Rep(i, 4) if(ip[i] < x.ip[i]) return true;
134         return false;
135     }
136     
137     bool operator== (const IP &x) const {
138         Rep(i, 4) if(ip[i] != x.ip[i]) return false;
139         return true;
140     }
141     
142     IP operator& (const IP &x) const {
143         IP ret;
144         Rep(i, 4) ret.ip[i] = ip[i] & x.ip[i];
145         return ret;
146     }
147     
148     IP operator| (const IP &x) const {
149         IP ret;
150         Rep(i, 4) ret.ip[i] = ip[i] | x.ip[i];
151         return ret;
152     }
153     
154     IP operator^ (const IP &x) const {
155         IP ret;
156         Rep(i, 4) ret.ip[i] = ip[i] ^ x.ip[i];
157         return ret;
158     }
159     
160     IP operator~ () const {
161         IP ret;
162         Rep(i, 4) ret.ip[i] = ~ip[i] & 0xff;
163         return ret;
164     }
165 };
166 
167 istream &operator>> (istream &in, IP &x) {
168     string tmp;
169     in >> tmp;
170     foreach(i, tmp) if(*i == ‘.‘) *i = ‘ ‘;
171     stringstream sin(tmp);
172     Rep(i, 4) sin >> x.ip[i];
173     return in;
174 }
175 
176 ostream &operator<< (ostream &out, const IP &x) {
177     Rep(i, 4) {
178         if(i) out << ".";
179         out << x.ip[i];
180     }
181     out << endl;
182     return out;
183 }
184 
185 int m;
186 IP mask, allIP[maxN];
187 
188 int main(){
189     //freopen("MyOutput.txt","w",stdout);
190     //freopen("input.txt","r",stdin);
191     INIT();
192     while(cin >> m) {
193         mask.allone();
194         
195         Rep(i, m) {
196             cin >> allIP[i];
197             if(i) mask = ~(allIP[i - 1] ^ allIP[i]) & mask;
198         }
199         
200         Rep(i, 4) {
201             if(mask.ip[i] != 255) {
202                 For(j, i + 1, 3) mask.ip[j] = 0;
203                 Rep(j, 9) {
204                     int x = (1 << j) - 1;
205                     x = ~x & 0xff;
206                     if((mask.ip[i] & x) == x) {
207                         mask.ip[i] = x;
208                         break;
209                     }
210                 }
211                 break;
212             }
213         }
214         
215         cout << (allIP[0] & mask) << mask;
216     }
217     return 0;
218 }