Submission #1305389

#	Time	Username	Problem	Language	Result	Execution time	Memory
1305389		veham	Valley (BOI19_valley)	C++20	0 / 100	139 ms	10272 KiB

valley

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<ll> vi;
typedef vector<ll> vl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
struct edge{
    ll v;
    ll w;
};
bool operator<(edge a, edge b){return a.w > b.w;}
bool operator==(edge a, edge b){return make_pair(a.v,a.w) == make_pair(b.v,b.w);};
typedef vector<edge> ve;
typedef vector<ve> vve;
#define MAX 1e17

int main(){
    ll N,S,Q,E;
    cin >> N >> S >> Q >> E;
    E--;
    vi A(N-1),B=A,Sh(S),IS(N,0),I(Q),R(Q);
    vl W(N-1);
    vl W2(N-1);
    for(ll i = 0;i < N-1;i++){
        cin >> A[i] >> B[i] >> W[i];
        A[i]--,B[i]--;
        W2[min(A[i],B[i])] = W[i];
    }
    for(ll i = 0;i < S;i++){
        cin >> Sh[i];
        IS[--Sh[i]] = 1;
    }
    for(ll i = 0;i < Q;i++){
        cin >> I[i] >> R[i];
        I[i]--,R[i]--;
    }

    vl DL(N,MAX),DR=DL;
    vl DLS(N,MAX),DRS=DLS;
    for(int i = 0;i < N;i++){
        if(IS[i]) DL[i] = 0, DLS[i] = 0;
        else if(i != 0 && DL[i-1]+W[i-1] < DL[i]) DL[i] = DL[i-1]+W[i-1], DLS[i] = DLS[i-1]+1;
    }
    for(int i = N-1;i >= 0;i--){
        if(IS[i]) DR[i] = 0, DRS[i] = 0;
        else if(i != N-1 && DR[i+1]+W[i] < DR[i]) DR[i] = DR[i+1]+W[i], DRS[i] = DRS[i+1]+1;
    }
    for(int q = 0;q < Q;q++){
        ll sep = min(A[I[q]],B[I[q]]);
        if(R[q] <= sep == E <= sep){
            cout << "escaped\n";
            continue;
        }
        ll ans = MAX;
        if(DRS[R[q]] == 0) ans = 0;
        else{
            if(clamp(sep,R[q],R[q]+DRS[R[q]]-1) != sep) ans = min(ans,DR[R[q]]);
            if(clamp(sep,R[q]-DLS[R[q]],R[q]-1) != sep) ans = min(ans,DL[R[q]]);
        }
        if(ans == MAX){
            cout << "oo\n";
            continue;    
        }
        cout << ans << '\n';
    }
    return 0;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 27
• Subtask 3: 0 / 23
• Subtask 4: 0 / 41