Cod sursa(job #2712610)

Utilizator Alex_tz307Lorintz Alexandru Alex_tz307 Data 26 februarie 2021 09:10:06
Problema Overlap Scor 16
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.95 kb
#include <bits/stdc++.h>

using namespace std;

ifstream fin("overlap.in");
ofstream fout("overlap.out");

const int NMAX = 8e2 + 2;
int N, x, y, prv[NMAX], nxt[NMAX], sol[NMAX];
pair<int,int> p[NMAX], init[NMAX];
map<pair<int,int>,int> match;

int main() {
    fin >> N;
    for(int i = 1; i <= N; ++i) {
        fin >> x >> y;
        init[i] = p[i] = make_pair(x, y);
        match[init[i]] = i;
    }
    // rotatie trigonometrica la 90 de grade: (-y, x)
    // rotatie in sensul acelor de ceasornic la 90 de grade: (y, -x)
    for(int rep = 0; rep < 4; ++rep) {
        for(int i = 1; i <= N; ++i) {
            swap(p[i].first, p[i].second);
            p[i].second *= -1;
        }
        for(int i = 2; i <= N; ++i) {
            int diffx = init[i].first - p[1].first,
                diffy = init[i].second - p[1].second;
            memset(prv, 0, sizeof(prv));
            memset(nxt, 0, sizeof(nxt));
            memset(sol, 0, sizeof(sol));
            for(int j = 1; j <= N; ++j)
                if(i != j) {
                    auto it = match.find({p[j].first + diffx, p[j].second + diffy});
                    if(it != match.end()) {
                        nxt[j] = it->second;
                        prv[it->second] = j;
                    }
                }
            bool ok = true;
            for(int j = 1; j <= N; ++j) {
                int curr = j;
                while(prv[curr] && prv[curr] != j)
                    curr = prv[curr];
                int lg = 0;
                while(!sol[curr] && curr) {
                    sol[curr] = lg++ + 1;
                    curr = nxt[curr];
                }
                if(lg & 1) {
                    ok = false;
                    break;
                }
            }
            if(ok) {
                for(int j = 1; j <= N; ++j)
                    fout << sol[j] << '\n';
                return 0;
            }
        }
    }
}