Submission #995499

#	Time	Username	Problem	Language	Result	Execution time	Memory
995499		Baytoro	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	476 ms	5840 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
#define fr first
#define sc second
#define pb push_back
//#define int long long 
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
void fopn(string name){
	freopen((name+".in").c_str(),"r",stdin);
	freopen((name+".out").c_str(),"w",stdout);
}
#define ll long long
const int N=3e4+5;
set<int> g[N];
bool used[N];
int dist[N];
int n,m;
void solve(){
	int n,m;cin>>n>>m;
	vector<int> b(m),p(m);
	for(int i=0;i<N;i++) dist[i]=1e9;
	for(int i=0;i<m;i++){
		cin>>b[i]>>p[i];
		g[b[i]].insert(-p[i]);
	}
	priority_queue<pair<int,int>, vector<pair<int,int> >, greater<pair<int,int> > > pq;
	pq.push(make_pair(0,b[0]));
	dist[b[0]]=0;
	while(!pq.empty()){
		int d=pq.top().fr;
		int v=pq.top().sc;
		pq.pop();
		if(dist[v]!=d) continue;
		for(auto it: g[v]){
			for(int j=1;v+j*-it<n;j++){
				if(dist[v+j*-it]>d+j){
					dist[v+j*-it]=d+j;
					pq.push(make_pair(d+j,v+j*-it));
				}
			}
			for(int j=1;v-j*-it>=0;j++){
				if(dist[v-j*-it]>d+j){
					dist[v-j*-it]=d+j;
					pq.push(make_pair(d+j,v-j*-it));
				}
			}
		}
	}
	if(dist[b[1]]==1e9) dist[b[1]]=-1;
	cout<<dist[b[1]];
}
signed main(){
	//fopn("paint");
	int t=1;//cin>>t;
	while(t--) solve();
}

Compilation message (stderr)

skyscraper.cpp: In function 'void fopn(std::string)':
skyscraper.cpp:10:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |  freopen((name+".in").c_str(),"r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:11:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |  freopen((name+".out").c_str(),"w",stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 43 / 43