Submission #410217

#	Time	Username	Problem	Language	Result	Execution time	Memory
410217		jeqcho	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	57 / 100	664 ms	262148 KiB

skyscraper

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

typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<pair<int,int>> vpi;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

#define pb push_back
#define rsz resize
#define sz(x) int(x.size())
#define all(x) begin(x), end(x)
#define fi first
#define se second

struct triple
{
	int a,b,c;
};

bool operator<(const triple &x, const triple &y)
{
	return x.a<y.a;
}

int const N=3e4;
int const sN=200;
int d[N][sN];
int const INF=1e9;
vector<triple>adj[N][sN];
bitset<sN> vis[N];
priority_queue<triple> q;

int main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	int n,m;
	cin>>n>>m;
	int b0,b1;
	F0R(i,m)
	{
		int bi,pi;
		cin>>bi>>pi;
		if(i==0)b0=bi;
		else if(i==1)b1=bi;
		if(pi>=sN)
		{
			int nxt=bi+pi;
			int cnt=1;
			while(nxt<n)
			{
				adj[bi][0].pb({nxt,0,cnt});
				++cnt;
				nxt+=pi;
			}
			nxt=bi-pi;
			cnt=1;
			while(nxt>=0)
			{
				adj[bi][0].pb({nxt,0,cnt});
				++cnt;
				nxt-=pi;
			}
		}
		else
		{
			adj[bi][0].pb({bi,pi,0});
		}
	}
	F0R(i,n)
	{
		fill(d[i],d[i]+sN,INF);
	}
	d[b0][0]=0;
	q.push({0,b0,0});
	while(!q.empty())
	{
		int pos = q.top().b;
		int pw = q.top().c;
		q.pop();
		if(vis[pos][pw])continue;
		vis[pos][pw]=1;
		if(pw!=0)
		{
			adj[pos][pw].pb({pos,0,0});
			int nxt=pos+pw;
			if(nxt<n)
			{
				adj[pos][pw].pb({nxt,pw,1});
			}
			nxt=pos-pw;
			if(nxt>=0)
			{
				adj[pos][pw].pb({nxt,pw,1});
			}
		}
		trav(e,adj[pos][pw])
		{
			int cand = d[pos][pw]+e.c;
			if(cand<d[e.a][e.b])
			{
				d[e.a][e.b]=cand;
				q.push({-cand,e.a,e.b});
			}
		}
		adj[pos][pw].clear();
	}
	if(d[b1][0]==INF)cout<<-1<<'\n';
	else cout<<d[b1][0]<<'\n';
	return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:114:12: warning: 'b1' may be used uninitialized in this function [-Wmaybe-uninitialized]
  114 |  if(d[b1][0]==INF)cout<<-1<<'\n';
      |     ~~~~~~~^
skyscraper.cpp:81:8: warning: 'b0' may be used uninitialized in this function [-Wmaybe-uninitialized]
   81 |  q.push({0,b0,0});
      |  ~~~~~~^~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 0 / 43