제출 #1280016

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1280016		hiepsimauhong	Valley (BOI19_valley)	C++20	100 / 100	219 ms	32776 KiB

valley

#include <bits/stdc++.h>

using namespace std;

#define int long long

#define FOR(I, L, R) for(int I(L) ; I <= (int)R ; ++I)
#define FOD(I, R, L) for(int I(R) ; I >= (int)L ; --I)
#define FOA(I, A) for(auto &I : A)

#define print(A,L,R) FOR(OK, L, R){if(A[OK]<=-oo / 10||A[OK]>=oo)cout<<"- ";else cout<<A[OK]<<' ';}cout<<'\n';
#define prints(A) FOA(OK, A){cout<<OK<<' ';}cout << '\n';
#define printz(A,L,R) FOR(OK, 0, L){FOR(KO, 0, R){if(A[OK][KO]>-oo&&A[OK][KO]<oo)cout<<A[OK][KO]<<' ';else cout << "- ";} cout << '\n';}cout << '\n';

#define fs first
#define sd second
#define ii pair<int,int>
#define iii pair<int, ii>
#define all(A) A.begin(), A.end()
#define quickly cin.tie(0) -> ios_base::sync_with_stdio(0);

const int N = 1e5 + 5;
const int mod = 1e9 + 7;
const int oo = 1e18;

int n, q, s, root, el;
int h[N], st[N], en[N], ans[N];
bool vis[N];
ii edge[N];

vector<ii> g[N], query[N];

struct Segment_tree{
        int sg[N << 2], lazy[N << 2];

        void push_down(int id, int l, int r){
                if(lazy[id]){
                        sg[id << 1] += lazy[id];
                        sg[id << 1 | 1] += lazy[id];

                        lazy[id << 1] += lazy[id];
                        lazy[id << 1 | 1] += lazy[id];

                        lazy[id] = 0;
                }
        }

        void update(int id, int l, int r, int u, int v, int val){
                if(l > v || r < u){
                        return;
                }
                if(u <= l && r <= v){
                        sg[id] += val;
                        lazy[id] += val;
                        return;
                }

                push_down(id, l, r);

                int mid = (l + r) >> 1;
                update(id << 1, l, mid, u, v, val);
                update(id << 1 | 1, mid + 1, r, u, v, val);

                sg[id] = min(sg[id << 1], sg[id << 1 | 1]);
        }

        int get(int id, int l, int r, int u, int v){
                if(l > v || r < u){
                        return oo;
                }
                if(u <= l && r <= v){
                        return sg[id];
                }

                push_down(id, l, r);

                int mid = (l + r) >> 1;
                return min(get(id << 1, l, mid, u, v), get(id << 1 | 1, mid + 1, r, u, v));
        }
} sg;

void DFS(int u, int par){
        st[u] = ++el;

        FOA(e, g[u]){
                int v = e.fs;
                int w = e.sd;

                if(v == par){
                        continue;
                }

                h[v] = h[u] + w;
                DFS(v, u);
        }
        en[u] = el;
}

void REROOT(int u, int par){
        FOA(i, query[u]){
                int v = i.fs, in = i.sd;
                ans[in] = sg.get(1, 1, n, st[v], en[v]);
        }

        FOA(e, g[u]){
                int v = e.fs;
                int w = e.sd;

                if(v == par){
                        continue;
                }
                sg.update(1, 1, n, st[v], en[v], -w);
                sg.update(1, 1, n, 1, st[v] - 1, w);
                sg.update(1, 1, n, en[v] + 1, n, w);

                REROOT(v, u);

                sg.update(1, 1, n, st[v], en[v], w);
                sg.update(1, 1, n, 1, st[v] - 1, -w);
                sg.update(1, 1, n, en[v] + 1, n, -w);
        }
}

signed main(){ quickly
        cin >> n >> s >> q >> root;

        FOR(i, 1, n - 1){
                int u, v, w;
                cin >> u >> v >> w;
                g[u].push_back({v, w});
                g[v].push_back({u, w});

                edge[i] = {u, v};
        }

        FOR(i, 1, s){
                int u; cin >> u;
                vis[u] = 1;
        }

        DFS(root, -1);

        FOR(i, 1, n){
                if(vis[i]){
                        sg.update(1, 1, n, st[i], st[i], h[i]);
                }
                else{
                        sg.update(1, 1, n, st[i], st[i], oo);
                }
        }

        FOR(i, 1, q){
                int id, u;
                cin >> id >> u;

                if(st[edge[id].fs] < st[edge[id].sd]){
                        swap(edge[id].fs, edge[id].sd);
                }

                int x = edge[id].fs;

                if(st[x] <= st[u] && en[u] <= en[x]){
                        query[u].push_back({x, i});
                }
                else{
                        ans[i] = -1;
                }
        }

        REROOT(root, -1);

        FOR(i, 1, q){
                if(ans[i] == -1){
                        cout << "escaped\n";
                }
                else{
                        if(ans[i] >= (int)1e15){
                                cout << "oo\n";
                        }
                        else{
                                cout << ans[i] << '\n';
                        }
                }
        }
}

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