Submission #995452

#	Time	Username	Problem	Language	Result	Execution time	Memory
995452		Baytoro	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	36 / 100	15 ms	5152 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;
vector<int> g[N];
int n,m;
bool used[2005][2005];
int distnce[2005];
void bfs(int x){
	queue<pair<int,pair<int,int> > > dq;
	for(auto it: g[x]){
		dq.push(make_pair(it,make_pair(x,0)));
		used[x][it]=1;
	}
	while(!dq.empty()){
		int p=dq.front().fr;
		int d=dq.front().sc.fr;
		int dist=dq.front().sc.sc;
		dq.pop();
		if(d+p<n){
			if(!used[d+p][p]){
				dq.push(make_pair(p,make_pair(d+p,dist+1)));
				distnce[d+p]=min(dist+1,distnce[d+p]);
				used[d+p][p]=1;
			}
		}
		if(d-p>=0){
			if(!used[d-p][p]){
				dq.push(make_pair(p,make_pair(d-p,dist+1)));
				distnce[d-p]=min(dist+1,distnce[d-p]);
				used[d-p][p]=1;
			}
		}
		for(auto it: g[d]){
			if(!used[d][it]){
				dq.push(make_pair(it,make_pair(d,dist)));
				used[d][it]=1;
			}
		}
	}
}
void solve(){
	for(int i=0;i<2005;i++) distnce[i]=1e9;
	cin>>n>>m;
	vector<int> b(m),p(m);
	for(int i=0;i<m;i++){
		cin>>b[i]>>p[i];
		g[b[i]].pb(p[i]);
	}
	distnce[b[0]]=0;
	bfs(b[0]);
	if(distnce[b[1]]>1e8) cout<<-1<<endl;
	else{
		cout<<distnce[b[1]]<<endl;
	}
}
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: 0 / 21
• Subtask 5: 0 / 43