Submission #539721

#	Time	Username	Problem	Language	Result	Execution time	Memory
539721		Eug1ena	Roller Coaster Railroad (IOI16_railroad)	C++14	0 / 100	196 ms	11556 KiB

railroad

#include <bits/stdc++.h>
using namespace std;
using lint = long long;
#define rep(i, n) for(int i = 0; i < int(n); i++)
#define rep2(i, l, n) for(int i = int(l); i < int(n); i++)
#define repr(i, n) for(int i = int(n) - 1; i >= 0; i--)
#define all(x) (x).begin(), (x).end()
inline int has(lint x, int k){ return (x >> k) & 1; };

struct UnionFind{
    int sz;
    vector<int> par;

    UnionFind(int n){
        sz = n;
        par.resize(n, -1);
    }

    int find(int k){
        if(par[k] == -1) return k;
        return par[k] = find(par[k]);
    }

    void unite(int a, int b){
        a = find(a), b = find(b);
        if(a == b) return;

        par[a] = b;
    }
};

lint plan_roller_coaster(vector<int> s_in, vector<int> t_in){
    int n = int(s_in.size());
    n++;

    int a[n], b[n];
    rep(i, n - 1){
        a[i] = s_in[i];
        b[i] = t_in[i];
    }
    a[n - 1] = 1e9 + 100;
    b[n - 1] = 1;

    vector<int> nums;
    rep(i, n){
        nums.push_back(a[i]);
        nums.push_back(b[i]);
    }
    sort(all(nums));
    nums.erase(unique(all(nums)), nums.end());

    int sz = int(nums.size());
    vector<int> deg(sz, 0);
    UnionFind uf(sz);
    rep(i, n){
        int a_idx = int(lower_bound(all(nums), a[i]) - nums.begin());
        int b_idx = int(lower_bound(all(nums), b[i]) - nums.begin());

        deg[a_idx]--;
        deg[b_idx]++;
        
        uf.unite(a_idx, b_idx);
    }

    int sum = deg[0];
    vector<int> big_light(sz - 1);
    rep(i, sz - 1){
        big_light[i] = sum;

        sum += deg[i];
    }

    rep(i, sz - 1){
        if(big_light[i] < 0){
            return 1;
        }
    }

    rep(i, sz - 1){
        if(big_light[i] > 0){
            uf.unite(i, i + 1);
        }
    }

    set<int> roots;
    rep(i, sz){
        roots.insert(uf.find(i));
    }
    if(roots.size() > 1) return 1;

    return 0;
}

// int main(){
//     // vector<int> s{1, 4, 5, 6};
//     // vector<int> t{7, 3, 8, 6};
//     // cout << plan_roller_coaster(s, t) << endl; // 3


//     vector<int> s{1, 5, 3};
//     vector<int> t{4, 2, 6};
//     cout << plan_roller_coaster(s, t) << endl; // 0
// }

• Subtask 1: 0 / 11
• Subtask 2: 0 / 23
• Subtask 3: 0 / 30
• Subtask 4: 0 / 36