Submission #959184

#	Time	Username	Problem	Language	Result	Execution time	Memory
959184		Abito	Railway Trip (JOI17_railway_trip)	C++17	5 / 100	22 ms	604 KiB

railway_trip

#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define ppb pop_back
#define ep insert
#define endl '\n'
#define elif else if
#define pow pwr
#define sqrt sqrtt
#define int long long
#define ll long long
typedef unsigned long long ull;
using namespace std;
const int N=105;
int a[N],n,q,k,dis[N][N];
bool vis[N][N];
void dijkstra(int s){
    for (int i=0;i<N;i++) for (int j=0;j<N;j++) dis[i][j]=INT_MAX,vis[i][j]=0;
    dis[s][a[s]]=0;
    priority_queue<vector<int>> pq;
    pq.push({0,s,a[s]});
    while (!pq.empty()){
        int x=pq.top()[1],y=pq.top()[2];
        pq.pop();
        if (vis[x][y]) continue;
        vis[x][y]=1;
        if (y>1){
            if (dis[x][y-1]>dis[x][y]){
                dis[x][y-1]=dis[x][y];
                pq.push({-dis[x][y-1],x,y-1});
            }
        }
        for (int i=x+1;i<=n;i++){
            if (a[i]<y) continue;
            if (dis[i][a[i]]>dis[x][y]+1){
                dis[i][a[i]]=dis[x][y]+1;
                pq.push({-dis[i][a[i]],i,a[i]});
            }break;
        }
        for (int i=x-1;i>0;i--){
            if (a[i]<y) continue;
            if (dis[i][a[i]]>dis[x][y]+1){
                dis[i][a[i]]=dis[x][y]+1;
                pq.push({-dis[i][a[i]],i,a[i]});
            }break;
        }
    }return;
}
int32_t main(){
    ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
    cin>>n>>k>>q;
    for (int i=1;i<=n;i++) cin>>a[i];
    while (q--){
        int x,y,ans=INT_MAX;
        cin>>x>>y;
        dijkstra(x);
        for (int j=1;j<=k;j++) ans=min(ans,dis[y][j]-1);
        cout<<ans<<endl;
    }
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 15
• Subtask 3: 0 / 25
• Subtask 4: 0 / 55