Submission #1194625

#	Time	Username	Problem	Language	Result	Execution time	Memory
1194625		steveonalex	Towns (IOI15_towns)	C++20	61 / 100	9 ms	328 KiB

towns

#include "towns.h"
#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(abs(a), abs(b));}
ll lcm(ll a, ll b){return abs(a) / gcd(a, b) * abs(b);}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ull mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
// mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

namespace Sub1{
    int solve(int n){

        int dih = 0;
        int u = 0;
        for(int i = 1; i < n; ++i) if (maximize(dih, getDistance(0, i))) 
            u = i;
        int v = 0;
        dih = 0;
        vector<int> dis1(n);
        for(int i = 0; i < n; ++i) if (i != u) {
            dis1[i] = getDistance(i, u);
            if (maximize(dih, dis1[i]))
                v = i;
        }

        vector<int> dis2(n);
        vector<int> left_dis(n), stick_out(n);
        dis2[u] = dih;
        left_dis[v] = dih;
        int ans = 1e9 + 69;
        for(int i = 0; i < n; ++i) if (i != u && i != v){
            int x = dis1[i], y = dis2[i] = getDistance(i, v);
            int cur = (x - y + dih) / 2;
            stick_out[i] = dis1[i] - cur;
            left_dis[i] = cur;
            maximize(cur, dih - cur);
            minimize(ans, cur);
        }

        vector<int> possible = left_dis; remove_dup(possible);
        for(int i: possible){
            if (max(i, dih - i) != ans) continue;
            array<int, 3> cnt; fill(ALL(cnt), 0);
            for(int j: left_dis) {
                if (j < i) cnt[0]++;
                else if (j == i) cnt[1]++;
                else cnt[2]++;
            }
            if (*max_element(ALL(cnt)) <= n / 2) return ans;
        }

        return -ans;

    }
}

namespace Sub2{
    int solve(int n){

        int dih = 0;
        int u = 0;
        for(int i = 1; i < n; ++i) if (maximize(dih, getDistance(0, i))) 
            u = i;
        int v = 0;
        dih = 0;
        vector<int> dis1(n);
        for(int i = 0; i < n; ++i) if (i != u) {
            dis1[i] = getDistance(i, u);
            if (maximize(dih, dis1[i]))
                v = i;
        }

        vector<int> dis2(n);
        vector<int> left_dis(n), stick_out(n);
        dis2[u] = dih;
        left_dis[v] = dih;
        int ans = 1e9 + 69;
        for(int i = 0; i < n; ++i) if (i != u && i != v){
            int x = dis1[i], y = dis2[i] = getDistance(i, v);
            int cur = (x - y + dih) / 2;
            stick_out[i] = dis1[i] - cur;
            left_dis[i] = cur;
            maximize(cur, dih - cur);
            minimize(ans, cur);
        }

        vector<int> possible = left_dis; remove_dup(possible);
        for(int i: possible){
            if (max(i, dih - i) != ans) continue;
            array<int, 3> cnt; fill(ALL(cnt), 0);
            vector<int> S;
            for(int j = 0; j < n; ++j) {
                if (left_dis[j] < i) cnt[0]++;
                else if (left_dis[j] == i) {
                    cnt[1]++;
                    S.push_back(j);
                }
                else cnt[2]++;
            }
            if (*max_element(ALL(cnt)) <= n / 2) return ans;
            if (max(cnt[0], cnt[2]) <= n / 2){
                vector<int> st;
                for(int j: S){
                    if (st.empty()) st.push_back(j);
                    else{
                        if (getDistance(st.back(), j) == stick_out[st.back()] + stick_out[j]) st.pop_back();
                        else st.push_back(j);
                    }
                }
                if (st.empty()) return ans;
                int cnt = 0;
                for(int j: S){
                    if (getDistance(st.back(), j) != stick_out[st.back()] + stick_out[j]) cnt++;
                    if (cnt > n / 2) break;
                }
                if (cnt <= n / 2) return ans;
            }
        }

        return -ans;

    }
}

int hubDistance(int n, int subtask){
    if (subtask == 1 || subtask == 2 || subtask == 4) return Sub1::solve(n);
    return Sub2::solve(n);
}

// int main(void){
//     ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);

//     clock_t start = clock();

//     cerr << "Time elapsed: " << clock() - start << " ms!\n";

//     return 0;
// }

• Subtask 1: 13 / 13
• Subtask 2: 12 / 12
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 13 / 13
• Subtask 6: 0 / 39