Submission #865046

#	Time	Username	Problem	Language	Result	Execution time	Memory
865046		LittleOrange	Designated Cities (JOI19_designated_cities)	C++17	13 / 100	198 ms	43344 KiB

designated_cities

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
struct obj{
    ll to,c0,c1;// to, back
};
int main(){
    ios::sync_with_stdio(0);cin.tie(0);
    ll n,q;
    cin >> n;
    vector<vector<obj>> con(n);
    ll tot = 0;
    for(ll i = 1;i<n;i++){
        ll a,b,c,d;
        cin >> a >> b >> c >> d;a--;b--;
        con[a].push_back({b,c,d});
        con[b].push_back({a,d,c});
        tot += c+d;
    }
    ll leaf_cnt = 0;
    for(auto &o : con) if (o.size()==1) leaf_cnt++;
    cin >> q;
    if (n<=16){
        vector<ll> ans(n+1,tot);
        ll cur = tot;
        vector<vector<ll>> used(n,vector<ll>(n,0));
        function<void(ll,ll)> dfs;
        dfs = [&](ll i, ll p){
            for(obj l : con[i]){
                if (l.to!=p){
                    if (!used[i][l.to]){
                        used[i][l.to] = 1;
                        cur -= l.c1;
                    }
                    dfs(l.to,i);
                }
            }
        };
        for(ll x = 1;x<(1<<n);x++){
            cur = tot;
            for(ll i = 0;i<n;i++) for(ll j = 0;j<n;j++) used[i][j] = 0;
            ll lvl = __builtin_popcountll(x);
            for(ll i = 0;i<n;i++) if(x>>i&1) dfs(i,-1);
            ans[lvl] = min(ans[lvl],cur);
        }
        while(q--){
            ll e;
            cin >> e;
            cout << ans[e] << "\n";
        }
        return 0;
    }
    vector<ll> dp(n,0);
    {
        function<ll(ll,ll)> dfs;
        dfs = [&](ll i, ll p){
            ll cur = 0;
            for(obj l : con[i]){
                if (l.to!=p){
                    cur += l.c1 + dfs(l.to,i);
                }
            }
            return cur;
        };
        dp[0] = dfs(0,-1);
    }
    {
        function<void(ll,ll,ll)> dfs;
        dfs = [&](ll i, ll p, ll v){
            dp[i] = v;
            for(obj l : con[i]){
                if (l.to!=p){
                    dfs(l.to,i,v+l.c0-l.c1);
                }
            }
        };
        dfs(0,-1,dp[0]);
    }
    while(q--){
        ll e;
        cin >> e;
        if (e>=leaf_cnt){
            cout << "0\n";
            continue;
        }
        if (e==1){
            ll ans = 0;
            for(ll i : dp) ans = max(i,ans);
            ans = tot-ans;
            cout << ans << "\n";
            continue;
        }
    }
}

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