Submission #286324

#	Time	Username	Problem	Language	Result	Execution time	Memory
286324		kartel	Highway Tolls (IOI18_highway)	C++14	51 / 100	297 ms	262148 KiB

highway

#include <bits/stdc++.h>
//#include "grader.cpp"
#include "highway.h"
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define in(x) freopen(x, "r", stdin)
#define out(x) freopen(x, "w", stdout)
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("fast-math")
//#pragma GCC optimize("no-stack-protector")
#define F first
#define S second
#define pb push_back
#define N +100500
#define M ll(1e9 + 7)
#define sz(x) (int)x.size()
#define re return
#define oo ll(1e9)
#define el '\n'
#define Max_A int(1e9)
//#define el endl
#define pii pair <int, int>
#define piii pair <int, pair <int, int> >
#define psi pair <string, int>
#define err ld(1e-9)
#define Max_S int(3e6)
#define last(x) (x).back()
#define all(x) (x).begin(), (x).end()
#define allr(x) (x).rbegin(), (x).rend()
#define arr_all(x, n) (x + 1), (x + 1 + n)
#define vi vector<int>
using namespace std;
//using namespace __gnu_pbds;
//typedef tree <int, null_type, less_equal <int> , rb_tree_tag, tree_order_statistics_node_update> ordered_set;
typedef long long ll;
typedef long double ld;

vector <pii> g[N];
ll base;
int ans[2], d[N], D[N];
vi w, lt;

bool gd(int n, int m, int x, ll base)
{
    for (int i = 0; i <= x; i++)
        w[i] = 0;

    for (int i = x + 1; i < m; i++)
        w[i] = 1;
    return (ask(w) == base);
}

int getft(int n, int m)
{
    for (int i = 0; i < m; i++)
        w[i] = 1;

    base = ask(w);

    int l = 0;
    int r = m - 1;
    while (l < r)
    {
        int md = (l + r) >> 1;

        if (gd(n, m, md, base))
            l = md + 1;
        else r = md;
    }

    return l;
}

int getlst(vi lt, int m)
{
    for (int i = 0; i < m; i++) w[i] = 0;
    base = ask(w);

    int l = -1;
    int r = sz(lt) - 1;
    while (l < r)
    {
        int md = (l + r + 1) >> 1;

        for (int i = 0; i < md; i++)
            w[lt[i]] = 0;

        for (int i = md; i < sz(lt); i++)
            w[lt[i]] = 1;

        if (ask(w) != base)
            l = md;
        else r = md - 1;
    }

    return l;
}

void dfs(int v, int pr)
{
    if (pr == -1)
         d[v] = 0;
    else d[v] = d[pr] + 1;

    for (auto u : g[v])
    {
        if (u.F == pr)
            continue;

        dfs(u.F, v);
    }
}

void dfs_0(int v, int pr, int de)
{
    D[v] = de;

    for (auto u : g[v])
    {
        if (u.F == pr)
            continue;

        lt.pb(u.S);
        dfs_0(u.F, v, de + 1);
    }
}

void find_pair(int n, vi u, vi v, int a, int b)
{
    int m = sz(u);

    for (int i = 0; i < m; i++)
    {
        g[u[i]].pb({v[i], i});
        g[v[i]].pb({u[i], i});
    }

    dfs(0, -1);

    w.resize(m);

    int ft = getft(n, m);

    int upper, lower;

    if (d[u[ft]] < d[v[ft]])
         upper = u[ft], lower = v[ft];
    else upper = v[ft], lower = u[ft];

    lt.pb(ft);
    D[lower] = -1;
    dfs_0(upper, lower, 0);

//    for (auto x : lt) cout << x << " ";
//    cout << el;
    int lst = getlst(lt, m);
//    cerr << lst << el;

    if (lst == -1)
        {
            int U = u[lt[0]];
            int V = v[lt[0]];

            if (D[U] > D[V])
                ans[0] = U;
            else ans[0] = V;
        }
    else
    {
        int U = u[lt[lst]];
        int V = v[lt[lst]];

        if (D[U] > D[V])
             ans[0] = U;
        else ans[0] = V;
    }

    lt.clear();
    lt.pb(ft);
    D[upper] = -1;
    dfs_0(lower, upper, 0);

    lst = getlst(lt, m);
//    cerr << lst << el;

    if (lst >= sz(lt))
        {
            int U = u[lt[0]];
            int V = v[lt[0]];

            if (D[U] > D[V])
                ans[1] = U;
            else ans[1] = V;
        }
    else {

        int U = u[lt[lst]];
        int V = v[lt[lst]];

        if (D[U] > D[V])
             ans[1] = U;
        else ans[1] = V;
    }
//    cout << ans[0] << " " << ans[1] << el;

    answer(ans[0], ans[1]);
}

/*int main()
{
    srand(time(0));
    cout.precision(3);
    cout << fixed;
    ios_base::sync_with_stdio(0);
    iostream::sync_with_stdio(0);
    ios::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);


//    in("input.txt");
//    out("output.txt");


}*/

/*
4 4
0110
0000
1101
1100
*/

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 6 / 6
• Subtask 4: 33 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31