Submission #1218681

#	Time	Username	Problem	Language	Result	Execution time	Memory
1218681		JooDdae	Roller Coaster Railroad (IOI16_railroad)	C++20	30 / 100	216 ms	37092 KiB

railroad

#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int chk[400400];
vector<int> v[400400];

void dfs(int u) {
    chk[u] = 1;
    for(auto x : v[u]) if(!chk[x]) dfs(x);
}

ll plan_roller_coaster(vector<int> s, vector<int> t) {
    priority_queue<array<int, 2>, vector<array<int, 2>>, greater<>> pq;
    s.push_back(1e9), t.push_back(1);
    int n = s.size();
    vector<int> V;
    for(int i=0;i<n;i++) V.push_back(s[i]), V.push_back(t[i]);
    sort(V.begin(), V.end());
    V.erase(unique(V.begin(), V.end()), V.end());

    for(int i=0;i<n;i++) s[i] = lower_bound(V.begin(), V.end(), s[i]) - V.begin() + 1;
    for(int i=0;i<n;i++) t[i] = lower_bound(V.begin(), V.end(), t[i]) - V.begin() + 1;

    int m = V.size();
    vector<int> S(m+1, 0);
    for(int i=0;i<n;i++) S[s[i]]++, S[t[i]]--, v[s[i]].push_back(t[i]);
    for(int i=1;i<m;i++) {
        S[i] += S[i-1];
        if(S[i] > 0) return 1;
        if(S[i] < 0) v[i].push_back(i+1);
    }
    dfs(1);
    return 1 - *min_element(chk+1, chk+1+m);
}

Compilation message (stderr)

railroad.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~
railroad_c.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~

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