Submission #605195

#	Time	Username	Problem	Language	Result	Execution time	Memory
605195		jhnah917	Designated Cities (JOI19_designated_cities)	C++14	23 / 100	2095 ms	18484 KiB

designated_cities

#pragma GCC optimize ("O3")
#pragma GCC target ("avx2")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

ll N, Q, Sum, CostTo1, C[202020], R[202020];
vector<pair<int,int>> G[202020];
int S[202020], U[202020];

void TreeDP(int v, int b=-1, ll up=0, ll dw=0){
    for(auto [i,w] : G[v]) if(i == b) CostTo1 += w, up += w;
    C[v] = dw - up;
    for(auto [i,w] : G[v]) if(i != b) TreeDP(i, v, up, dw+w);
}

inline ll CostToRoot(int root){ return CostTo1 + C[root]; }

pair<ll,ll> V[202020]; int sz, st;
ll DFS(int v, int b=-1){
    ll mx = 0;
    for(auto [i,w] : G[v]){
        if(i == b || U[i]) continue;
        ll nxt = DFS(i, v) + w;
        if(nxt > mx) swap(nxt, mx);
        if(nxt > 0) V[sz++] = {nxt, st};
    }
    return mx;
}
void CostFromRoot(int root){
    sz = 0;
    for(auto [i,w] : G[root]) if(!U[i]) V[sz++] = {DFS(st=i, -1) + w, i};
}

int GetSize(int v, int b=-1){
    S[v] = 1;
    for(auto [i,w] : G[v]) if(i != b && !U[i]) S[v] += GetSize(i, v);
    return S[v];
}

int GetCent(int v, int tot){
    int b = -1;
    while(true){
        int nxt = -1;
        for(auto [i,w] : G[v]) if(i != b && !U[i] && S[i]*2 > tot) { nxt = i; break; }
        if(nxt == -1) break;
        else b = v, v = nxt;
    }
    return v;
}

int GetAnswer(int v){
    v = GetCent(v, GetSize(v)); U[v] = 1;
    CostFromRoot(v);
    sort(V, V+sz, greater<>());

    ll now = CostToRoot(v);
    for(int k=2; k<=N; k++){
        if(k-2 < sz) now += V[k-2].first;
        R[k] = min(R[k], Sum - now);
    }

    int mx2 = -1;
    for(int i=1; i<sz; i++) if(V[i].second != V[0].second) { mx2 = i; break; }
    if(mx2 != -1){
        now = CostToRoot(v) + V[mx2].first;
        for(int k=2; k<=N; k++){
            int idx = k-2 < mx2 ? k-2 : k-1;
            if(idx < sz) now += V[idx].first;
            R[k] = min(R[k], Sum - now);
        }
    }

    return v;
}

int main(){
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    cin >> N;
    for(int i=1; i<N; i++){
        int a, b, c, d; cin >> a >> b >> c >> d; Sum += c + d;
        G[a].emplace_back(b, c); G[b].emplace_back(a, d);
    }
    TreeDP(1);

    memset(R, 0x3f, sizeof R);
    R[1] = Sum - CostTo1 - *max_element(C+1, C+N+1);

    queue<int> que; que.push(1);
    while(!que.empty()){
        int v = que.front(); que.pop();
        v = GetAnswer(v); U[v] = 1;
        for(auto [i,w] : G[v]) if(!U[i]) que.push(i);
    }

    cin >> Q;
    for(int i=1; i<=Q; i++){
        int t; cin >> t;
        cout << R[t] << "\n";
    }
}

Compilation message (stderr)

designated_cities.cpp: In function 'void TreeDP(int, int, ll, ll)':
designated_cities.cpp:12:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   12 |     for(auto [i,w] : G[v]) if(i == b) CostTo1 += w, up += w;
      |              ^
designated_cities.cpp:14:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   14 |     for(auto [i,w] : G[v]) if(i != b) TreeDP(i, v, up, dw+w);
      |              ^
designated_cities.cpp: In function 'll DFS(int, int)':
designated_cities.cpp:22:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   22 |     for(auto [i,w] : G[v]){
      |              ^
designated_cities.cpp: In function 'void CostFromRoot(int)':
designated_cities.cpp:32:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   32 |     for(auto [i,w] : G[root]) if(!U[i]) V[sz++] = {DFS(st=i, -1) + w, i};
      |              ^
designated_cities.cpp: In function 'int GetSize(int, int)':
designated_cities.cpp:37:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   37 |     for(auto [i,w] : G[v]) if(i != b && !U[i]) S[v] += GetSize(i, v);
      |              ^
designated_cities.cpp: In function 'int GetCent(int, int)':
designated_cities.cpp:45:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   45 |         for(auto [i,w] : G[v]) if(i != b && !U[i] && S[i]*2 > tot) { nxt = i; break; }
      |                  ^
designated_cities.cpp: In function 'int main()':
designated_cities.cpp:93:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   93 |         for(auto [i,w] : G[v]) if(!U[i]) que.push(i);
      |                  ^

• Subtask 1: 6 / 6
• Subtask 2: 0 / 7
• Subtask 3: 0 / 9
• Subtask 4: 17 / 17
• Subtask 5: 0 / 17
• Subtask 6: 0 / 44