Submission #780536

#	Time	Username	Problem	Language	Result	Execution time	Memory
780536		mrwang	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	81 ms	6004 KiB

skyscraper

#include<bits/stdc++.h>
#define TASKNAME "codeforce"
#define pb push_back
#define pli pair<ll,ll>
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL);
using namespace std;
using ll=int;
const ll maxN=3e4+100;
const ll inf=1e9+7;
const ll mod=1e9+7;
ll n;
ll dis[maxN];
priority_queue<pli,vector<pli>,greater<pli>>pq;
vector<ll>lon[maxN];
vector<pli>be[maxN];
ll p[maxN],b[maxN];
const ll block=175;
vector<ll>vec[block+2][block+2];
ll m;
void dij(ll s)
{
    for(int i=0;i<n;i++) dis[i]=inf;
    dis[s]=0;
    pq.push({dis[s],s});
    while(!pq.empty())
    {
        ll u=pq.top().se;
        ll d=pq.top().fi;
        pq.pop();
        if(d>dis[u]) continue;
        if(u==b[2])
        {
            break;
        }
        for(auto i:lon[u])
        {
            for(int j=u-p[i];j>=0;j-=p[i])
            {
                if(dis[j]>dis[u]+(u-j)/p[i])
                {
                    dis[j]=dis[u]+(u-j)/p[i];
                    pq.push({dis[j],j});
                }
            }
            for(int j=u+p[i];j<n;j+=p[i])
            {
                if(dis[j]>dis[u]+(j-u)/p[i])
                {
                    dis[j]=dis[u]+(j-u)/p[i];
                    pq.push({dis[j],j});
                }
            }
        }
        for(auto cc:be[u])
        {
            ll i=cc.fi;
            ll j=u%i;
            ll k=cc.se;
            ll pos=vec[i][j][k];
            ll pos2=k>0?vec[i][j][k-1]:0;
            for(int q=pos-i;q>=pos2;q-=i)
            {
                if(dis[q]>dis[pos]+(pos-q)/i)
                {
                    dis[q]=dis[pos]+(pos-q)/i;
                    pq.push({dis[q],q});
                }
            }
            pos2=(k+1<vec[i][j].size())?vec[i][j][k+1]:n-1;
            for(int q=pos+i;q<=pos2;q+=i)
            {
                if(dis[q]>dis[pos]+(q-pos)/i)
                {
                    dis[q]=dis[pos]+(q-pos)/i;
                    pq.push({dis[q],q});
                }
            }
        }
    }
}

void solve()
{
    cin >> n >> m;
    for(int i=1;i<=m;i++)
    {
        cin >> b[i] >> p[i];
    }
    for(int i=1;i<=m;i++)
    {
        if(p[i]>block)
        {
            lon[b[i]].pb(i);
        }
        else
        {
            vec[p[i]][b[i]%p[i]].pb(b[i]);
        }
    }
    for(int i=1;i<=block;i++)
    {
        for(int j=0;j<i;j++)
        {
            sort(vec[i][j].begin(),vec[i][j].end());
            for(int k=0;k<vec[i][j].size();k++)
            {
                be[vec[i][j][k]].pb({i,k});
            }
        }
    }
    dij(b[1]);
    if(dis[b[2]]==inf) cout << -1<<'\n';
    else cout << dis[b[2]];
}
int main()
{
    fastio
    //freopen(TASKNAME".INP","r",stdin);
    //freopen(TASKNAME".OUT","w",stdout);
    solve();
}

Compilation message (stderr)

skyscraper.cpp: In function 'void dij(ll)':
skyscraper.cpp:71:22: warning: comparison of integer expressions of different signedness: 'll' {aka 'int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |             pos2=(k+1<vec[i][j].size())?vec[i][j][k+1]:n-1;
      |                   ~~~^~~~~~~~~~~~~~~~~
skyscraper.cpp: In function 'void solve()':
skyscraper.cpp:107:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  107 |             for(int k=0;k<vec[i][j].size();k++)
      |                         ~^~~~~~~~~~~~~~~~~

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