Submission #710905

#	Time	Username	Problem	Language	Result	Execution time	Memory
710905		JJAnawat	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	756 ms	25920 KiB

skyscraper

#include<bits/stdc++.h>

using namespace std;
using ti = tuple<int,int,int>;

const int inf=1e9;

int n,m;
int dis[30005][175];
vector<int> bg[30005],sm[30005];
int b[30005],p[30005];

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> n >> m;
    int sq=sqrt(n);
    for(int i=0;i<m;i++){
        cin >> b[i] >> p[i];
        if(p[i]<=sq)
            sm[b[i]].push_back(p[i]);
        else
            bg[b[i]].push_back(p[i]);
    }

    for(int i=0;i<n;i++)
        for(int j=0;j<175;j++)
            dis[i][j]=inf;

    priority_queue<ti,vector<ti>,greater<ti>> pq;
    dis[b[0]][0]=0;
    pq.push({0,b[0],0});
    while(!pq.empty()){
        auto [du,u,pw]=pq.top();
        pq.pop();
        if(du>dis[u][pw])
            continue;
        if(pw){
            if(u-pw>=0){
                if(du+1<dis[u-pw][pw]){
                    dis[u-pw][pw]=du+1;
                    pq.push({du+1,u-pw,pw});
                }
                if(du+1<dis[u-pw][0]){
                    dis[u-pw][0]=du+1;
                    pq.push({du+1,u-pw,0});
                }
            }
            if(u+pw<n){
                if(du+1<dis[u+pw][pw]){
                    dis[u+pw][pw]=du+1;
                    pq.push({du+1,u+pw,pw});
                }
                if(du+1<dis[u+pw][0]){
                    dis[u+pw][0]=du+1;
                    pq.push({du+1,u+pw,0});
                }
            }
        }
        else{
            for(auto pl:bg[u]){
                for(int v=u,cnt=0;v<n;v+=pl,cnt++){
                    if(dis[v][0]>du+cnt){
                        dis[v][0]=du+cnt;
                        pq.push({du+cnt,v,0});
                    }
                }
                for(int v=u,cnt=0;v>=0;v-=pl,cnt++){
                    if(dis[v][0]>du+cnt){
                        dis[v][0]=du+cnt;
                        pq.push({du+cnt,v,0});
                    }
                }
            }
            for(auto pl:sm[u]){
                if(dis[u][pl]>du){
                    dis[u][pl]=du;
                    pq.push({du,u,pl});
                }
            }
        }
    }
    int mn=inf;
    for(int i=0;i<=sq;i++)
        mn=min(mn,dis[b[1]][i]);
    if(mn==inf)
        mn=-1;
    cout << mn;
}

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