Cod sursa(job #2712613)

Utilizator Alex_tz307Lorintz Alexandru Alex_tz307 Data 26 februarie 2021 09:14:45
Problema Overlap Scor 16
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.94 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].first *= -1;
        }
        for(int i = 2; i <= N; ++i) {
            int diffx = init[i].first - p[1].first,
                diffy = init[i].second - p[1].second;
            for(int j = 1; j <= N; ++j)
                prv[j] = nxt[j] = sol[j] = 0;
            for(int j = 1; j <= N; ++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)
                if(!sol[j]) {
                    int curr = j;
                    while(prv[curr] && prv[curr] != j)
                        curr = prv[curr];
                    int lg = 0;
                    while(curr && !sol[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;
            }
        }
    }
}