Submission #946910

#	Time	Username	Problem	Language	Result	Execution time	Memory
946910		gaga999	Hard route (IZhO17_road)	C++17	0 / 100	3 ms	13916 KiB

road

#include <cstdio>
#include <stdio.h>
#include <iostream>
#include <math.h>
#include <vector>
#include <queue>
#include <stack>
#include <deque>
#include <algorithm>
#include <utility>
#include <set>
#include <map>
#include <stdlib.h>
#include <cstring>
#include <string.h>
#include <string>
#include <sstream>
#include <assert.h>
#include <climits>
#include <sstream>
#include <numeric>
#include <time.h>
#include <limits.h>
#include <list>
#include <bitset>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <iomanip>
#include <complex>
#include <chrono>
#include <fstream>
#include <functional>
#include <unistd.h>
// #pragma GCC optimize("Ofast,no-stack-protector")
// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx,avx2,bmi,bmi2,lzcnt,popcnt")
#define lowbit(x) ((x) & -(x))
#define ml(a, b) ((1ll * (a) * (b)) % M)
#define tml(a, b) (a) = ((1ll * (a) * (b)) % M)
#define ad(a, b) ((0ll + (a) + (b)) % M)
#define tad(a, b) (a) = ((0ll + (a) + (b)) % M)
#define mi(a, b) ((0ll + M + (a) - (b)) % M)
#define tmi(a, b) (a) = ((0ll + M + (a) - (b)) % M)
#define tmin(a, b) (a) = min((a), (b))
#define tmax(a, b) (a) = max((a), (b))
#define iter(a) (a).begin(), (a).end()
#define riter(a) (a).rbegin(), (a).rend()
#define init(a, b) memset((a), (b), sizeof(a))
#define cpy(a, b) memcpy((a), (b), sizeof(a))
#define uni(a) a.resize(unique(iter(a)) - a.begin())
#define size(x) (int)x.size()
#define pb emplace_back
#define mpr make_pair
#define ls(i) ((i) << 1)
#define rs(i) ((i) << 1 | 1)
#define INF 0x3f3f3f3f
#define NIF 0xc0c0c0c0
#define eps 1e-9
#define F first
#define S second
#define AC cin.tie(0)->sync_with_stdio(0)
using namespace std;
typedef long long llt;
typedef pair<int, int> pii;
typedef pair<double, double> pdd;
typedef pair<llt, llt> pll;
typedef complex<double> cd;
// const int M = 998244353;

// random_device rm;
// mt19937 rg(rm());
// default_random_engine rg(rm());
// uniform_int_distribution<int> rd(INT_MIN, INT_MAX);
// uniform_real_distribution<double> rd(0, M_PI);

void db() { cerr << "\n"; }
template <class T, class... U>
void db(T a, U... b) { cerr << a << " ", db(b...); }

inline char gc()
{
    const static int SZ = 1 << 16;
    static char buf[SZ], *p1, *p2;
    if (p1 == p2 && (p2 = buf + fread(p1 = buf, 1, SZ, stdin), p1 == p2))
        return -1;
    return *p1++;
}
void rd() {}
template <typename T, typename... U>
void rd(T &x, U &...y)
{
    x = 0;
    bool f = 0;
    char c = gc();
    while (!isdigit(c))
        f ^= !(c ^ 45), c = gc();
    while (isdigit(c))
        x = (x << 1) + (x << 3) + (c ^ 48), c = gc();
    f && (x = -x), rd(y...);
}

template <typename T>
void prt(T x)
{
    if (x < 0)
        putchar('-'), x = -x;
    if (x > 9)
        prt(x / 10);
    putchar((x % 10) ^ 48);
}

const int N = 5e5 + 5;
vector<int> eg[N];
llt ans = 0, num = 1;
int dp[N];
struct P
{
    int v0, v1, v2, nm;
    P() : v0(-INF), v1(-INF), v2(-INF), nm(0) {}
    void add(int v)
    {
        if (v > v0)
            swap(v, v0);
        if (v > v1)
            swap(v, v1);
        if (v > v2)
            swap(v, v2), nm = 1;
        if (v == v2)
            nm++;
    }
    inline llt gv()
    {
        return (0ll + v0) * (v1 + v2);
    }
    inline llt gn()
    {
        if (v0 == v1 && v1 == v2)
            return ((1ll + nm) * (2ll + nm)) >> 1;
        if (v0 == v1)
            return nm << 1;
        if (v1 == v2)
            return ((1ll + nm) * nm) >> 1;
        return nm;
    }
    inline void ck() { db(v0, v1, v2, nm); }
};

void dfs(int u, int fa)
{
    for (int v : eg[u])
    {
        if (v == fa)
            continue;
        tmax(dp[u], dp[v] + 1);
        dfs(v, u);
    }
}

void slv(int u, int fa)
{
    int mx = 0, sc = -INF;
    P cr;
    for (int v : eg[u])
    {
        cr.add(dp[v] + 1);
        tmax(sc, dp[v] + 1);
        if (sc > mx)
            swap(sc, mx);
    }
    // db(u), cr.ck();
    llt vv = cr.gv(), nn = cr.gn();
    if (vv >= ans)
    {
        if (vv ^ ans)
            num = 0;
        num += nn, ans = vv;
    }
    int pr = dp[u];
    for (int v : eg[u])
    {
        if (v == fa)
            continue;
        if (dp[v] + 1 == mx)
            dp[u] = sc;
        else
            dp[u] = mx;
        slv(v, u);
    }
    dp[u] = pr;
}

signed main()
{
    int n, x, y;
    rd(n);
    for (int i = 1; i < n; i++)
    {
        rd(x, y);
        eg[x].pb(y);
        eg[y].pb(x);
    }
    dfs(1, -1), slv(1, -1);
    if (!ans)
        assert(num == 1);
    prt(ans), putchar(' ');
    prt(num), putchar('\n');
}

• Subtask 1: 0 / 19
• Subtask 2: 0 / 33
• Subtask 3: 0 / 48