Submission #704779

#	Time	Username	Problem	Language	Result	Execution time	Memory
704779		becaido	Trobojnica (COCI19_trobojnica)	C++17	110 / 110	244 ms	24896 KiB

trobojnica

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,popcnt,sse4,abm")
#include <bits/stdc++.h>
using namespace std;

#ifdef WAIMAI
#define debug(HEHE...) cout << "[" << #HEHE << "] : ", dout(HEHE)
void dout() {cout << '\n';}
template<typename T, typename...U>
void dout(T t, U...u) {cout << t << (sizeof...(u) ? ", " : ""), dout(u...);}
#else
#define debug(...) 7122
#endif

#define ll long long
#define Waimai ios::sync_with_stdio(false), cin.tie(0)
#define FOR(x,a,b) for (int x = a, I = b; x <= I; x++)
#define pb emplace_back
#define F first
#define S second

const int SIZE = 2e5 + 5;

int n;
string s;
set<tuple<int, int, int>> st;
set<pair<int, int>> p[4];
vector<tuple<int, int, int>> ans;

bool in(int i) {
    auto it = st.lower_bound({i, 0, 0});
    return it != st.end() && get<0>(*it) == i;
}

int color(int i) {
    auto it = st.lower_bound({i, 0, 0});
    return get<2>(*it);
}

void connect(int l, int r) {
    auto lit = st.lower_bound({l, 0, 0});
    auto [l1, r1, c1] = *lit;
    st.erase(lit);
    auto rit = st.lower_bound({r, 0, 0});
    auto [l2, r2, c2] = *rit;
    st.erase(rit);
    ans.pb(l1, r2, 6 - c1 - c2);
    st.emplace(l1, r2, 6 - c1 - c2);

    auto it = st.lower_bound({l1, 0, 0});
    if (it != st.begin()) lit = prev(it);
    else lit = --st.end();
    if (it != --st.end()) rit = next(it);
    else rit = st.begin();

    tie(l1, r1, c1) = *lit;
    tie(l2, r2, c2) = *it;
    if (c1 != c2) p[6 - c1 - c2].emplace(l1, r1);

    tie(l1, r1, c1) = *it;
    tie(l2, r2, c2) = *rit;
    if (c1 != c2) p[6 - c1 - c2].emplace(l1, r1);
}

void solve() {
    cin >> n >> s;
    s = " " + s;

    int cnt[4] = {};
    FOR (i, 1, n) cnt[s[i] - '0']++;
    FOR (i, 1, 3) {
        int x = n - 3 - cnt[i];
        if (x % 2 == 0) {
            cout << "NE\n";
            return;
        }
        x = (x + 1) / 2;
        if (x < 0) {
            cout << "NE\n";
            return;
        }
        cnt[i] = x;
    }

    FOR (i, 1, n) {
        st.emplace(i, i % n + 1, s[i] - '0');
        if (s[i] != s[i % n + 1]) p[6 - (s[i] - '0') - (s[i % n + 1] - '0')].emplace(i, i % n + 1);
    }

    while (st.size() > 3) {
        bool ok = 0;
        while (ok == 0) {
            ok = 1;

            int l = 0, r = 0, ii = 0;
            FOR (i, 1, 3) if (cnt[i] && p[i].size()) {
                tie(l, r) = *p[i].begin();
                p[i].erase(p[i].begin());
                ii = i;
                break;
            }

            if (!in(l) || !in(r)) {
                ok = 0;
                continue;
            }
            int cl = color(l), cr = color(r);
            if (cl == cr || 6 - cl - cr != ii) {
                ok = 0;
                continue;
            }

            cnt[ii]--;
            connect(l, r);
        }
    }
    cout << "DA\n";
    for (auto [a, b, c] : ans) cout << a << ' ' << b << ' ' << c << '\n';
}

int main() {
    Waimai;
    solve();
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 50 / 50