Submission #1147841

#	Time	Username	Problem	Language	Result	Execution time	Memory
1147841		Theo830	Jakarta Skyscrapers (APIO15_skyscraper)	C++20	100 / 100	909 ms	58664 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e9+7;
const ll MOD = 998244353;
typedef pair<ll,ll> ii;
#define iii pair<ii,ll>
#define f(i,a,b) for(ll i = a;i < b;i++)
#define pb push_back
#define vll vector<ll>
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
///I hope I will get uprating and don't make mistakes
///I will never stop programming
///sqrt(-1) Love C++
///Please don't hack me
///@TheofanisOrfanou Theo830
///Think different approaches (bs,dp,greedy,graphs,shortest paths,mst)
///Stay Calm
///Look for special cases
///Beware of overflow and array bounds
///Think the problem backwards
///Training
const ll val = 200;
ll dist[30005][val+5];
int main(void){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll n,m;
    cin>>n>>m;
    ll b[m],p[m];
    vector<ll>ex[n];
    f(i,0,m){
        cin>>b[i]>>p[i];
        ex[b[i]].pb(p[i]);
    }
    ll best[n];
    f(i,0,n){
        best[i] = INF;
        f(j,0,val+5){
            dist[i][j] = INF;
        }
    }
    best[b[0]] = 0;
    priority_queue<ii,vector<ii>,greater<ii> >pq,q[val+5];
    pq.push(ii(0,b[0]));
    while(!pq.empty()){
        ii f = pq.top();
        pq.pop();
        ll w = f.F,u = f.S;
        if(best[u] < w){
            continue;
        }
        for(auto x:ex[u]){
            if(x >= val){
                ll cur = u;
                ll posa = 0;
                while(cur < n){
                    if(best[cur] > w + posa){
                        best[cur] = w + posa;
                        pq.push(ii(best[cur],cur));
                    }
                    cur += x;
                    posa++;
                }
                cur = u;
                posa = 0;
                while(cur >= 0){
                    if(best[cur] > w + posa){
                        best[cur] = w + posa;
                        pq.push(ii(best[cur],cur));
                    }
                    cur -= x;
                    posa++;
                }
            }
            else{
                if(dist[u][x] > w){
                    dist[u][x] = w;
                    q[x].push(ii(w,u));
                }
            }
        }
        f(j,0,val){
            while(!q[j].empty()){
                ii f = q[j].top();
                q[j].pop();
                ll x = f.F,y = f.S;
                if(dist[y][j] < x){
                    continue;
                }
                ll pos = y - j;
                if(pos >= 0 && dist[pos][j] > x+1){
                    dist[pos][j] = x+1;
                    q[j].push(ii(dist[pos][j],pos));
                    if(best[pos] > dist[pos][j]){
                        best[pos] = dist[pos][j];
                        pq.push(ii(best[pos],pos));
                    }
                }
                pos = y + j;
                if(pos < n && dist[pos][j] > x+1){
                    dist[pos][j] = x+1;
                    q[j].push(ii(dist[pos][j],pos));
                    if(best[pos] > dist[pos][j]){
                        best[pos] = dist[pos][j];
                        pq.push(ii(best[pos],pos));
                    }
                }
            }
        }
    }
    ll ans = best[b[1]];
    if(ans == INF){
        ans = -1;
    }
    cout<<ans<<"\n";
}

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