Submission #1013299

#	Time	Username	Problem	Language	Result	Execution time	Memory
1013299		c2zi6	Highway Tolls (IOI18_highway)	C++14	12 / 100	233 ms	262144 KiB

highway

#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<VPI> VVPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
typedef vector<VL> VVL;
typedef vector<VVL> VVVL;
typedef vector<VPL> VVPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<class T>
using indset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#include "highway.h"

int n, m;
VVPI gp;
VI depth;
VI parind;

void dfs(int u = 0, int pind = -1) {
    parind[u] = pind;
    for (auto[v, ind] : gp[u]) if (ind != pind) {
        depth[v] = depth[u]+1;
        dfs(v, ind);
    }
}

void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
    n = N;
    m = U.size();
    gp = VVPI(n);
    rep(i, m) {
        gp[U[i]].pb({V[i], i});
        gp[V[i]].pb({U[i], i});
    }
    depth = parind = VI(n);
    dfs();
    ll base = ask(VI(m));
    int d = base/A;

    VI b;
    rep(u, n) if (depth[u] == d) b.pb(u);

    auto f = [&](int x) {
        VI W(m);
        replr(i, 0, x) W[parind[b[i]]] = true;
        return ask(W) > base;
    };

    int l = -1, r = b.size()-1;
    while (l + 1 < r) {
        int m = (l + r) / 2;
        if (f(m)) r = m;
        else l = m;
    }
    answer(0, b[r]);
}

/*ask(VI w);*/
/*answer(int s, int t)*/

Compilation message (stderr)

highway.cpp: In function 'void dfs(int, int)':
highway.cpp:41:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   41 |     for (auto[v, ind] : gp[u]) if (ind != pind) {
      |              ^

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