oj.uz

Submission #995843

# Submission time Handle Problem Language Result Execution time Memory
995843 2024-06-10T02:00:57 Z whatthemomooofun1729 Love Polygon (BOI18_polygon) C++17
75 / 100
 333 ms 36300 KB 
#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#include <stack>
#include <map>
#include <queue>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cstring>
#include <cmath>
#include <functional>
#include <cassert>
#include <iomanip>
#include <numeric>
#include <bitset>
#include <sstream>
#include <chrono>
#include <random>

#define ff first
#define ss second
#define PB push_back
#define sz(x) int(x.size())
#define rsz resize
#define fch(xxx, yyy) for (auto xxx : yyy) // abusive notation
#define all(x) (x).begin(),(x).end()
#define eps 1e-9

// more abusive notation (use at your own risk):
//#define int ll

using namespace std;
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vll = vector<ll>;

// debugging
void __print(int x) {std::cerr << x;}
void __print(ll x) {std::cerr << x;} /* remember to uncomment this when not using THE MACRO */
void __print(unsigned x) {std::cerr << x;}
void __print(ull x) {std::cerr << x;}
void __print(float x) {std::cerr << x;}
void __print(double x) {std::cerr << x;}
void __print(ld x) {std::cerr << x;}
void __print(char x) {std::cerr << '\'' << x << '\'';}
void __print(const char *x) {std::cerr << '\"' << x << '\"';}
void __print(const string& x) {std::cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V> void __print(const pair<T, V> &x) {std::cerr << '{'; __print(x.ff); std::cerr << ", "; __print(x.ss); std::cerr << '}';}
template<typename T> void __print(const T& x) {int f = 0; std::cerr << '{'; for (auto &i: x) std::cerr << (f++ ? ", " : ""), __print(i); std::cerr << "}";}
void _print() {std::cerr << "]\n";}
template <typename T, typename... V> void _print(T t, V... v) {__print(t); if (sizeof...(v)) std::cerr << ", "; _print(v...);}
void println() {std::cerr << ">--------------------<" << endl;}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

// templates
template <class T> bool ckmin(T &a, const T &b) {return b<a ? a = b, 1 : 0;}
template <class T> bool ckmax(T &a, const T &b) {return b>a ? a = b, 1 : 0;}
template <class T> using gr = greater<T>;
template <class T> using vc = vector<T>;
template <class T> using p_q = priority_queue<T>;
template <class T> using pqg = priority_queue<T, vc<T>, gr<T>>;
template <class T1, class T2> using pr = pair<T1, T2>;
mt19937_64 rng_ll(chrono::steady_clock::now().time_since_epoch().count());
int rng(int M) {return (int)(rng_ll()%M);} /*returns any random number in [0, M) */

// const variables
constexpr int INF = (int)2e9;
constexpr int MOD = 998244353;
constexpr ll LL_INF = (ll)3e18;
constexpr int mod = (int)1e9 + 7;
constexpr ll inverse = 500000004LL; // inverse of 2 modulo 1e9 + 7

void setIO(const string& str) {// fast input/output
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    if (str.empty()) return;
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
}

int N, cnt = 1;
map<string, int> mp;
vc<vi> adj;
vc<vi> fuck, comps;
vi dp[2], vst, f, cc;

void dfs(int v) {
    dp[0][v] = 0, dp[1][v] = 1;
    vst[v] = 1;
    vi children;
    fch(u, adj[v]) if (!vst[u]) {
        dfs(u);
        children.PB(u);
        dp[1][v] += dp[0][u];
    }
    //debug(v);
    //debug(children);
    if (sz(children) == 0) return;
    int C = sz(children);
    vi psum(C), ssum(C);
    for (int i = 0; i < C; ++i) {
        psum[i] = (i > 0 ? psum[i - 1] : 0) + dp[0][children[i]];
    }
    for (int i = C-1; i >= 0; --i) {
        ssum[i] = (i < C - 1 ? ssum[i + 1] : 0) + dp[0][children[i]];
    }
    //debug(psum);
    //debug(ssum);
    for (int i = 0; i < C; ++i) {
        ckmax(dp[0][v], dp[1][children[i]] + (i > 0 ? psum[i - 1] : 0) + (i < C - 1 ? ssum[i + 1] : 0));
    }
    //debug(dp[0][v], dp[1][v]);
}

void undo(int v) {
    for (int i = 0; i < sz(comps[cc[v]]); ++i) {
        vst[comps[cc[v]][i]] = 0;
    }
}

void why_not(int v) {
    for (int i = 0; i < sz(comps[cc[v]]); ++i) {
        vst[comps[cc[v]][i]] = 1;
    }
}

void dfs1(int v) {
    fch(u, fuck[v]) if (cc[u] != cc[v]) {
        cc[u] = cc[v];
        dfs1(u);
    }
}

signed main() { // TIME YOURSELF !!!
    setIO("");
    cin >> N;
    if (N & 1) {
        cout << "-1\n";
        return 0;
    }
    adj.rsz(N+1), dp[0].rsz(N+1, 0), dp[1].rsz(N+1, 1), vst.rsz(N+1), f.rsz(N+1), cc.rsz(N+1, -1), comps.rsz(N+1);
    fuck.rsz(N+1);
    for (int i = 0; i < N; ++i) {
        string a, b;
        cin >> a >> b;
        if (mp[a] == 0) mp[a] = cnt++;
        if (mp[b] == 0) mp[b] = cnt++;
        adj[mp[b]].PB(mp[a]);
        fuck[mp[b]].PB(mp[a]);
        fuck[mp[a]].PB(mp[b]);
        f[mp[a]] = mp[b];
    }
    { // finding the connected components
        for (int i = 1; i <= N; ++i) {
            if (cc[i] == -1) {
                cc[i] = i;
                dfs1(i);
            }
        }
        for (int i = 1; i <= N; ++i) {
            comps[cc[i]].PB(i);
        }
    }
    //debug(mp);
    int ans = 0;
    for (int i = 1; i <= N; ++i) {
        if (!vst[i]) {
            //debug(i);
            int t = f[i], h = f[f[i]];
            while (t != h) {
                t = f[t];
                h = f[f[h]];
            }
            int L = 1;
            t = f[t];
            while (t != h) {
                L++;
                t = f[t];
            }
            //debug(L, t);
            if (L == 1) {
                vst[t] = 1;
                dfs(t);
                ans += dp[0][t];
                //debug(dp[0][t]);
            } else {
                int res = 0;
                int s = f[t];
                // 2: (t, f[t]) are not connected
                dfs(t);
                ckmax(res, dp[0][t]);
                undo(t);
                // 1: (t, f[t]) are connected
                if (L > 2) {
                    vst[t] = vst[s] = 1;
                    int temp = t;
                    t = f[s];
                    while (f[t] != temp) {
                        t = f[t];
                    }
                    dfs(t);
                    int sum = dp[0][t];
                    t = temp;
                    fch(u, adj[t]) if (!vst[u]) {
                        dfs(u);
                        sum += dp[0][u];
                    }
                    fch(u, adj[s]) if (!vst[u]) {
                        dfs(u);
                        sum += dp[0][u];
                    }
                    ckmax(res, sum);
                } else if (L == 2) {
                    vst[t] = vst[s] = 1;
                    int sum = 2;
                    fch(u, adj[t]) if (!vst[u]) {
                        dfs(u);
                        sum += dp[0][u];
                    }
                    fch(u, adj[s]) if (!vst[u]) {
                        dfs(u);
                        sum += dp[0][u];
                    }
                    ckmax(res, sum);
                }
                ans += res;
            }
            why_not(i);
        }
    }
    assert(ans <= N);
    cout << N - ans << '\n';
    return 0;
}

// TLE -> TRY NOT USING DEFINE INT LONG LONG
// CE -> CHECK LINE 45
// 5000 * 5000 size matrices are kinda big (potential mle)
// Do something, start simpler

Compilation message

polygon.cpp: In function 'void setIO(const string&)':
polygon.cpp:88:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
polygon.cpp:89:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 508 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 360 KB Output is correct
13 Correct 0 ms 456 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 1 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 333 ms 33504 KB Output is correct
5 Correct 290 ms 24400 KB Output is correct
6 Correct 309 ms 35016 KB Output is correct
7 Correct 0 ms 348 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 282 ms 23240 KB Output is correct
2 Correct 283 ms 28116 KB Output is correct
3 Correct 236 ms 28868 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 295 ms 36300 KB Output is correct
6 Correct 271 ms 24788 KB Output is correct
7 Correct 283 ms 24916 KB Output is correct
8 Correct 273 ms 26112 KB Output is correct
9 Correct 238 ms 24528 KB Output is correct
10 Correct 175 ms 24944 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct

Subtask #4
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 508 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 360 KB Output is correct
13 Correct 0 ms 456 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 344 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 333 ms 33504 KB Output is correct
20 Correct 290 ms 24400 KB Output is correct
21 Correct 309 ms 35016 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 282 ms 23240 KB Output is correct
24 Correct 283 ms 28116 KB Output is correct
25 Correct 236 ms 28868 KB Output is correct
26 Correct 0 ms 348 KB Output is correct
27 Correct 295 ms 36300 KB Output is correct
28 Correct 271 ms 24788 KB Output is correct
29 Correct 283 ms 24916 KB Output is correct
30 Correct 273 ms 26112 KB Output is correct
31 Correct 238 ms 24528 KB Output is correct
32 Correct 175 ms 24944 KB Output is correct
33 Correct 0 ms 348 KB Output is correct
34 Correct 1 ms 348 KB Output is correct
35 Correct 0 ms 348 KB Output is correct
36 Correct 0 ms 348 KB Output is correct
37 Correct 309 ms 25908 KB Output is correct
38 Incorrect 289 ms 26564 KB Output isn't correct
39 Halted 0 ms 0 KB -