Submission #1160890

#	Time	Username	Problem	Language	Result	Execution time	Memory
1160890		SmuggingSpun	Rail (IOI14_rail)	C++20	100 / 100	49 ms	1616 KiB

rail

#include<bits/stdc++.h>
#include "rail.h"
using namespace std;
void findLocation(int n, int first, int location[], int stype[]){
    map<pair<int, int>, int>cache;
    auto get = [&] (int i, int j){
        if(i == j){
            return 0;
        }
        if(i > j){
            swap(i, j);
        }
        auto it = cache.find(make_pair(i, j));
        if(it != cache.end()){
            return it->second;
        }
        return cache[make_pair(i, j)] = getDistance(i, j);
    };
    int d = stype[0] = 1;
    location[0] = first;
    for(int i = 2; i < n; i++){
        if(get(0, i) < get(0, d)){
            d = i;
        }
    }
    if(n == 1){
        return;
    }
    stype[d] = 2;
    set<pair<int, int>>C, D;
    C.emplace(first, 0);
    D.emplace(location[d] = first + get(0, d), d);
    int lc, rd;
    auto in_c = [&] (int p){
        auto it = C.lower_bound(make_pair(p, -1));
        return it != C.end() && it->first == p;
    };
    auto in_d = [&] (int p){
        auto it = D.lower_bound(make_pair(p, -1));
        return it != D.end() && it->first == p;
    };
    auto check_1 = [&] (int i){
        int loc = location[lc] + get(lc, i), m = (loc + location[rd] - get(rd, i)) >> 1;
        if(in_c(m) || (!in_d(m) && location[0] < m)){
            D.emplace(location[i] = loc, i);
            stype[i] = 2;
            return true;
        }
        return false;
    };
    auto check_2 = [&] (int i){
        C.emplace(location[i] = location[rd] - get(rd, i), i);
        stype[i] = 1;
    };
    vector<int>p(n - 1);
    iota(p.begin(), p.end(), 1);
    sort(p.begin(), p.end(), [&] (int i, int j){
        return get(0, i) < get(0, j);
    });
    p.erase(p.begin());
    for(int& i : p){
        lc = (*C.begin()).second;
        rd = (*D.rbegin()).second;
        if(!check_1(i)){
            check_2(i);
        }
    }
}

• Subtask 1: 8 / 8
• Subtask 2: 22 / 22
• Subtask 3: 26 / 26
• Subtask 4: 44 / 44