Submission #605354

#	Time	Username	Problem	Language	Result	Execution time	Memory
605354		jhnah917	Designated Cities (JOI19_designated_cities)	C++14	100 / 100	937 ms	32332 KiB

designated_cities

#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);
}

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

vector<pair<ll,ll>> CostFromRoot(int root){
    vector<pair<ll,ll>> vec;
    function<ll(int,int,int)> dfs = [&](int st, int v, int b) -> ll {
        ll mx = 0;
        for(auto [i,w] : G[v]){
            if(i == b || U[i]) continue;
            ll nxt = dfs(st, i, v) + w;
            if(nxt > mx) swap(nxt, mx);
            if(nxt > 0) vec.emplace_back(nxt, st);
        }
        return mx;
    };
    for(auto [i,w] : G[root]) if(!U[i]) vec.emplace_back(dfs(i, i, -1) + w, i);
    return vec;
}

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){
    for(auto [i,w] : G[v]) if(i != b && !U[i] && S[i]*2 > tot) return GetCent(i, tot, v);
    return v;
}

void GetAnswer(int v=1){
    v = GetCent(v, GetSize(v)); U[v] = 1;
    auto vec = CostFromRoot(v);
    sort(vec.begin(), vec.end(), greater<>());

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

    int mx2 = -1;
    for(int i=1; i<vec.size(); i++) if(vec[i].second != vec[0].second) { mx2 = i; break; }
    if(mx2 != -1){
        now = CostToRoot(v) + vec[mx2].first;
        vec.erase(vec.begin()+mx2);
        for(int k=2; k-2<vec.size(); k++){
            now += vec[k-2].first;
            R[k] = min(R[k], Sum - now);
        }
    }

    for(auto [i,w] : G[v]) if(!U[i]) GetAnswer(i);
}

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);
    GetAnswer();
    for(int i=2; i<=N; i++) R[i] = min(R[i], R[i-1]);

    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:10:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   10 |     for(auto [i,w] : G[v]) if(i == b) CostTo1 += w, up += w;
      |              ^
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) TreeDP(i, v, up, dw+w);
      |              ^
designated_cities.cpp: In lambda function:
designated_cities.cpp:23:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   23 |         for(auto [i,w] : G[v]){
      |                  ^
designated_cities.cpp: In function 'std::vector<std::pair<long long int, long long int> > CostFromRoot(int)':
designated_cities.cpp:31:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   31 |     for(auto [i,w] : G[root]) if(!U[i]) vec.emplace_back(dfs(i, 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, int)':
designated_cities.cpp:42:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   42 |     for(auto [i,w] : G[v]) if(i != b && !U[i] && S[i]*2 > tot) return GetCent(i, tot, v);
      |              ^
designated_cities.cpp: In function 'void GetAnswer(int)':
designated_cities.cpp:52:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |     for(int k=2; k-2<vec.size(); k++){
      |                  ~~~^~~~~~~~~~~
designated_cities.cpp:58:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |     for(int i=1; i<vec.size(); i++) if(vec[i].second != vec[0].second) { mx2 = i; break; }
      |                  ~^~~~~~~~~~~
designated_cities.cpp:62:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |         for(int k=2; k-2<vec.size(); k++){
      |                      ~~~^~~~~~~~~~~
designated_cities.cpp:68:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   68 |     for(auto [i,w] : G[v]) if(!U[i]) GetAnswer(i);
      |              ^

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