Submission #1042586

#	Time	Username	Problem	Language	Result	Execution time	Memory
1042586		Theo830	Fire (BOI24_fire)	C++17	40 / 100	2100 ms	13228 KiB

Main

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e9+7;
const ll MOD = 998244353;
typedef pair<ll,ll> ii;
#define iii pair<ii,ll>
#define f(i,a,b) for(ll i = a;i < b;i++)
#define pb push_back
#define vll vector<ll>
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
///I hope I will get uprating and don't make mistakes
///I will never stop programming
///sqrt(-1) Love C++
///Please don't hack me
///@TheofanisOrfanou Theo830
///Think different approaches (bs,dp,greedy,graphs,shortest paths,mst)
///Stay Calm
///Look for special cases
///Beware of overflow and array bounds
///Think the problem backwards
///Training
int main(void){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll n,m;
    cin>>n>>m;
    vector<ii>ex,ar;
    f(i,0,n){
        ll s,e;
        cin>>s>>e;
        if(s < e){
            ex.pb(ii(s,e));
        }
        else{
            ar.pb((ii(s,e)));
            ex.pb(ii(0,e));
            ex.pb(ii(s,m));
        }
    }
    sort(all(ex));
    ll ans = INF;
    for(auto x:ar){
        ll res = 1;
        ll pos = 0;
        ll cur = x.S;
        while(pos < ex.size() && cur < x.F){
            ll go = cur;
            while(pos < ex.size() && ex[pos].F <= cur){
                go = max(go,ex[pos].S);
                pos++;
            }
            res++;
            if(cur == go){
                break;
            }
            cur = go;
        }
        if(cur < x.F){
            res = INF;
        }
        ans = min(ans,res);
    }
    if(ans == INF){
        ans = -1;
    }
    cout<<ans<<"\n";
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:49:19: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |         while(pos < ex.size() && cur < x.F){
      |               ~~~~^~~~~~~~~~~
Main.cpp:51:23: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |             while(pos < ex.size() && ex[pos].F <= cur){
      |                   ~~~~^~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 17 / 17
• Subtask 3: 9 / 9
• Subtask 4: 0 / 13
• Subtask 5: 0 / 21
• Subtask 6: 0 / 26