Submission #202049

#	Time	Username	Problem	Language	Result	Execution time	Memory
202049		theStaticMind	Designated Cities (JOI19_designated_cities)	C++14	16 / 100	1831 ms	67084 KiB

designated_cities

#include<bits/stdc++.h>
#define pb push_back
#define ii pair<int,int>
#define all(x) (x).begin(),(x).end()
#define INF 100000000000000000
#define modulo 1000000007
#define mod 998244353
#define int long long int
using namespace std;

vector<int> adj[200005];
vector<int> val(200005);
vector<int> Ans(200005, 0);
vector<int> sub(200005, 1);
vector<pair<ii, int> > V(200005);
vector<bool> mark(200005, false);
unordered_map<int, int> cost;
int S = 0;
int _hash(ii a){
      return a.first * 1e6 + a.second;
}
void dfs1(int x, int pre, int& v){
      for(int i = 0; i < adj[x].size(); i++){
            int y = adj[x][i];
            if(y == pre) continue;
            v += cost[_hash({y, x})];
            dfs1(y, x, v);
      }
}
void dfs2(int x, int pre, int v){
      val[x] = v;
      for(int i = 0; i < adj[x].size(); i++){
            int y = adj[x][i];
            if(y == pre) continue;
            dfs2(y, x, v - cost[_hash({y, x})] + cost[_hash({x, y})]);
      }
}
void dfs3(int x, int pre){
      sub[x] = 1;
      for(int i = 0; i < adj[x].size(); i++){
            int y = adj[x][i];
            if(y == pre || mark[y]) continue;
            dfs3(y, x);
            sub[x] += sub[y];
      }
}
void dfs4(int x, int pre, int sum, ii& mx){
      if(sum > mx.first){
            mx = {sum, x};
      }
       for(int i = 0; i < adj[x].size(); i++){
            int y = adj[x][i];
            if(y == pre || mark[y]) continue;
            dfs4(y, x, sum + cost[_hash({x, y})], mx);
      }
}
int find_centroid(int x, int pre, int sum){
      for(int i = 0; i < adj[x].size(); i++){
            int y = adj[x][i];
            if(y == pre || mark[y])continue;
            if(sub[y] > sum / 2)return find_centroid(y, x, sum);
      }
      return x;
}
void solve(int x){
      dfs3(x, -1);
      x = find_centroid(x, -1, sub[x]);
      ii mx = {0, x};
      pair <ii, int> ans = {{x, x}, 0};
      for(int i = 0; i < adj[x].size(); i++){
            int y = adj[x][i];
            if(mark[y])continue;
            ii temp = {cost[_hash({x, y})], y};
            dfs4(y, x, cost[_hash({x, y})], temp);
            if(ans.second < mx.first + temp.first){
                  ans.first = {mx.second, temp.second};
                  ans.second = mx.first + temp.first;
            }
            if(temp.first > mx.first){
                  swap(temp, mx);
            }
      }
      V[x] = ans;
      mark[x] = true;
      for(int i = 0; i < adj[x].size(); i++){
            int y =adj[x][i];
            if(mark[y])continue;
            solve(y);
      }
}
int32_t main(){
      ios_base::sync_with_stdio(false);
      cin.tie(NULL);
//      freopen("q.gir","r",stdin);
//      freopen("q.cik","w",stdout);
      int n;
      cin >> n;
      for(int i = 0; i < n - 1; i++){
            int x, y, a, b;
            cin >> x >> y >> a >> b;
            adj[x].pb(y);
            adj[y].pb(x);
            cost[_hash({x, y})] = a;
            cost[_hash({y, x})] = b;
            S += a + b;
      }
      int w = 0;
      dfs1(1, 0, w);
      dfs2(1, 0, w);
      Ans[1] = S - *max_element(all(val));
      solve(1);
      Ans[2] = INF;
      for(int i = 1; i <= n; i++)Ans[2] = min(Ans[2], (S - val[i]) - V[i].second);
      int q;
      cin >> q;
      while(q--){
            int k;
            cin >> k;
            cout << Ans[k] << "\n";
      }
}

Compilation message (stderr)

designated_cities.cpp: In function 'void dfs1(long long int, long long int, long long int&)':
designated_cities.cpp:23:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for(int i = 0; i < adj[x].size(); i++){
                      ~~^~~~~~~~~~~~~~~
designated_cities.cpp: In function 'void dfs2(long long int, long long int, long long int)':
designated_cities.cpp:32:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for(int i = 0; i < adj[x].size(); i++){
                      ~~^~~~~~~~~~~~~~~
designated_cities.cpp: In function 'void dfs3(long long int, long long int)':
designated_cities.cpp:40:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for(int i = 0; i < adj[x].size(); i++){
                      ~~^~~~~~~~~~~~~~~
designated_cities.cpp: In function 'void dfs4(long long int, long long int, long long int, std::pair<long long int, long long int>&)':
designated_cities.cpp:51:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
        for(int i = 0; i < adj[x].size(); i++){
                       ~~^~~~~~~~~~~~~~~
designated_cities.cpp: In function 'long long int find_centroid(long long int, long long int, long long int)':
designated_cities.cpp:58:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for(int i = 0; i < adj[x].size(); i++){
                      ~~^~~~~~~~~~~~~~~
designated_cities.cpp: In function 'void solve(long long int)':
designated_cities.cpp:70:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for(int i = 0; i < adj[x].size(); i++){
                      ~~^~~~~~~~~~~~~~~
designated_cities.cpp:85:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for(int i = 0; i < adj[x].size(); i++){
                      ~~^~~~~~~~~~~~~~~

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