Submission #1203076

#	Time	Username	Problem	Language	Result	Execution time	Memory
1203076		onbert	Roller Coaster Railroad (IOI16_railroad)	C++20	0 / 100	145 ms	25692 KiB

railroad

#include "railroad.h"
#include <bits/stdc++.h>
using namespace std;
#define int long long
const int INF = 1e15;
const int maxn = 4e5 + 5;
int sz;
vector<int> vals = {-INF};
int dc(int x) {return lower_bound(vals.begin(), vals.end(), x) - vals.begin();}
int n;
vector<int> adj[maxn];
int sum[maxn];
bool dp[maxn];


long long plan_roller_coaster(vector<int32_t> s, vector<int32_t> t) {
    n = s.size();
    for (int i=0;i<n;i++) {
        vals.push_back(s[i]); vals.push_back(t[i]);
    }
    sort(vals.begin(), vals.end());
    vals.erase(unique(vals.begin(), vals.end()), vals.end());
    sz = vals.size() - 1;
    for (int i=0;i<n;i++) s[i] = dc(s[i]), t[i] = dc(t[i]);

    for (int i=0;i<n;i++) {
        adj[s[i]].push_back(t[i]);
    }
    for (int i=1;i<=sz;i++) sort(adj[i].begin(), adj[i].end());

    for (int i=0;i<n;i++) sum[s[i]]--, sum[t[i]]++;
    for (int i=1;i<=sz;i++) sum[i] += sum[i-1];
    if (*min_element(sum+1, sum+sz+1) <= -2) return 1;
    dp[sz+1] = 1;
    for (int i=sz;i>=1;i--) {
        if (sum[i] == -1 || !dp[i+1]) dp[i] = 0;
        else dp[i] = 1;
        for (int v:adj[i]) if (v > i && dp[v+1]) dp[i] = 1;
    }
    if (!dp[1]) return 1;
    return 0;
}

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: 0 / 30
• Subtask 4: 0 / 36