제출 #1285697

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1285697		fern	Star Trek (CEOI20_startrek)	C++20	23 / 100	1095 ms	13912 KiB

startrek

/*
 *|---------------------------------------------|*
 *|       Author  : Le Hoang An                 |*
 *|     From  :  Bien Hoa Gifted High School    |*
 *|---------------------------------------------|*
 *|                ADOMINATION                  |*
 *|---------------------------------------------|*
*/
#pragma GCC optimize("02,unroll-loops")
#include <bits/stdc++.h>
#define f0(i, n) for(int i = 0; i < n; i++)
#define fi first
#define se second
#define pb push_back
#define ep emplace_back
#define el cout << "\n";
//#define sz(A) (int)A.size()
#define FOR(i, l, r) for (int i = l; i <= r; i++)
#define FOD(i, r, l) for (int i = r; i >= l; i--)
#define REP(i, n) for (int i = 0, _n = (n); i < _n; i++)
#define all(x) x.begin(), x.end()
#define AtLeastThirdPrizeVOI          \
    ios_base::sync_with_stdio(false); \
    cin.tie(NULL);                    \
    cout.tie(NULL);
#define AnWillWin signed main()
using namespace std;
typedef long long ll;
typedef pair<int, int> ii;
typedef string str;
typedef vector<int> vi;
using ull = unsigned long long;
const int maxn = 150000;
const ll inf = 5e18;
const int mod = 998244353;
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define __builtin_popcount __builtin_popcountll

template <class X, class Y>
bool maximize(X &x, const Y &y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}

template <class X, class Y>
bool minimize(X &x, const Y &y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

void file(){
    #define TASK "BanhsEs"
    if(fopen(TASK ".INP", "r")){
        freopen(TASK ".INP", "r", stdin);
        freopen(TASK ".OUT", "w", stdout);
    }
}
bool canWin[maxn];
int cnt[maxn], cric[maxn], sumW[maxn], sumL[maxn], dp[maxn];
vi adj[maxn];
void dfs_game(int u, int par){
    canWin[u] = false;
    cnt[u] = 0;
    for(int v : adj[u]) if(v != par){
        dfs_game(v, u);
        canWin[u] |= !canWin[v];
        cnt[u] += !canWin[v];
    }
}
void calc(int u){
    if(canWin[u]){
        if(cnt[u] >= 2) cric[u] = 0;
        else cric[u] = sumL[u];
    }
    else cric[u] =  sumW[u] + 1;
}
void dfs_cric(int u, int p){
    sumW[u] = sumL[u] = 0;
    for(int v : adj[u]) if(v != p){
        dfs_cric(v, u);
        if(canWin[v]) sumW[u] += cric[v];
        else sumL[u] += cric[v];
    }
    calc(u);
}
void reroot(int u, int v){
    if(canWin[v]) sumW[v] -= cric[v];
    else {
        sumL[u] -= cric[v];
        cnt[u]--;
    }
    canWin[u] = (cnt[u] > 0);
    calc(u);

    if(canWin[u]) sumW[v] += cric[u];
    else{
        sumL[v] += cric[u];
        cnt[v]++;
    }
    canWin[v] = (cnt[v] > 0);
    calc(v);
}
int loser = 0, c = 0;
void dfs(int u, int p){
    loser += !canWin[u];
    c += (canWin[u] ? 1 : -1) * cric[u];

    for(int v : adj[u]) if(v != p){
        reroot(u, v); dfs(v, u);
        reroot(v, u);
    }
}
int Pow(int x, int n){
    if(n == 0) return 1;
    int p = Pow(x, n / 2);
    p = 1ll * p * p % mod;
    if(n & 1) p = 1ll * p * x % mod;
    return p;
}
int n, D;
AnWillWin{
    AtLeastThirdPrizeVOI;
    file();
    cin >> n >> D;
    FOR(i, 1, n - 1){
        int u, v; cin >> u >> v;
        adj[u].pb(v); adj[v].pb(u);
    }
    c = 0;
    FOR(r, 1, n){
        dfs_game(r, 0);
        dfs_cric(r, 0);
        c += (canWin[r] ? 1 : -1) * cric[r];
        loser += !canWin[r];
    }

    while(c < 0) c += mod;
    dp[0] = loser;
    FOR(i, 1, D - 1)
        dp[i] = (loser * Pow(n, 2 * i) + c * dp[i - 1]) % mod;
    dfs_game(1, 0); dfs_cric(1, 0);
    if(canWin[1])
        cout << (Pow(n, 2 * D) - dp[D - 1] * cric[1] % mod + 1ll * mod * mod) % mod;
    else cout << dp[D - 1] * cric[1] % mod;
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

startrek.cpp: In function 'void file()':
startrek.cpp:61:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |         freopen(TASK ".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
startrek.cpp:62:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |         freopen(TASK ".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 0
• Subtask 2: 0 / 7
• Subtask 3: 8 / 8
• Subtask 4: 15 / 15
• Subtask 5: 0 / 15
• Subtask 6: 0 / 20
• Subtask 7: 0 / 20
• Subtask 8: 0 / 15