Submission #264638

#	Time	Username	Problem	Language	Result	Execution time	Memory
264638		jeqcho	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	57 / 100	1098 ms	4096 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 f first
#define s second

int N,M;
int const m=3e4, n=3e4;
int B[m];
int P[m];
vi sky[n];
int dist[m];
priority_queue<pii>q;
bitset<n> vis;
bitset<m> pro;

int sqrtN = sqrt(N);

void activate(int loc, map<int,int> &adjnow)
{
    int newloc;
    trav(now, sky[loc])
    {
        if(P[now]>sqrtN)
        {
            for(int i=1; loc+i*P[now]<N; ++i)
            {
                newloc = loc+i*P[now];
                if(vis[newloc])continue;
                if(!sky[newloc].empty())
                {
                    if(adjnow.find(newloc)!=adjnow.end())
                    {
                        adjnow[newloc] = min(adjnow[newloc], i);
                    }
                    else adjnow.insert({newloc, i});
                }
            }
            for(int i=-1; loc+i*P[now]>=0; --i)
            {
                newloc = loc+i*P[now];
                if(vis[newloc])continue;
                if(!sky[newloc].empty())
                {
                    if(adjnow.find(newloc)!=adjnow.end())
                    {
                        adjnow[newloc] = min(adjnow[newloc], -i);
                    }
                    else adjnow.insert({newloc, -i});
                }
            }
        }
        else
        {
            newloc = loc+P[now];
            if(!vis[newloc]&&loc+P[now]<N)
            {
                sky[newloc].pb(P[now]);
                if(adjnow.find(newloc)!=adjnow.end())
                {
                    adjnow[newloc] = min(adjnow[newloc], 1);
                }
                else adjnow.insert({newloc, 1});
            }
            newloc = loc-P[now];
            if(!vis[newloc]&&loc+P[now]<N)
            {
                sky[newloc].pb(P[now]);
                if(adjnow.find(newloc)!=adjnow.end())
                {
                    adjnow[newloc] = min(adjnow[newloc], 1);
                }
                else adjnow.insert({newloc, 1});
            }
        }
    }
}


void dij(int x)
{
    dist[x]=0;
    q.push({0,x});
    int b,w;
    map<int,int> adjnow;
    while(!q.empty())
    {
        int a = q.top().s;
        q.pop();
        if(vis[a])continue;
        vis[a]=1;
        if(a==B[1])return;
        adjnow.clear();
        activate(a, adjnow);
        trav(e, adjnow)
        {
            b=e.f;
            w=e.s;
            if(dist[a]+w<dist[b])
            {
                dist[b]=dist[a]+w;
                q.push({-dist[b],b});
            }
        }
    }
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin>>N>>M;
    F0R(i,M)
    {
        cin>>B[i]>>P[i];
        sky[B[i]].pb(i);
    }
    int INF=1e9;
    F0R(loc,N)
    {
        dist[loc]=INF;
    }
    dij(B[0]);
    if(dist[B[1]]==INF)cout<<-1<<'\n';
    else cout<<dist[B[1]]<<'\n';
    return 0;
}

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