Submission #112237

#	Time	Username	Problem	Language	Result	Execution time	Memory
112237		thebes	Designated Cities (JOI19_designated_cities)	C++14	100 / 100	705 ms	41764 KiB

designated_cities

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
const int MN = 2e5+5;
ll N, Q, i, ans[MN], tot, cur, x, y, a, b, dist[MN], w[2*MN], par[MN];
vector<pair<ll,ll>> adj[MN], ord;
struct pq{bool operator()(const pair<ll,ll>&i,const pair<ll,ll>&j){return i.second>j.second;}};
priority_queue<pair<ll,ll>,vector<pair<ll,ll>>,pq> q;
ll meh(ll n,ll p){
    ll cur = 0;
    for(auto v : adj[n]){
        if(v.first==p) continue;
        cur+=w[v.second^1]+meh(v.first,n);
    }
    return cur;
}
void dfs(ll n,ll p){
    ans[1]=max(ans[1],cur);
    for(auto v : adj[n]){
        if(v.first==p) continue;
        cur += w[v.second]-w[v.second^1]; dfs(v.first,n);
        cur -= w[v.second]-w[v.second^1];
    }
}
pair<ll,ll> dfs2(ll n,ll p){
    pair<ll,ll> tmp(n,0);
    for(auto v : adj[n]){
        if(v.first==p) continue;
        auto tt = dfs2(v.first, n);
        tt.second += w[v.second];
        if(tt.second<tmp.second) ord.push_back(tt);
        else{swap(tmp,tt); ord.push_back(tt);}
    }
    return tmp;
}
int main(){
    memset(ans,-1,sizeof(ans));
    for(scanf("%lld",&N),i=1;i<N;i++){
        scanf("%lld%lld%lld%lld",&x,&y,&a,&b);
        adj[x].push_back({y,2*i-2});
        adj[y].push_back({x,2*i-1});
        w[2*i-2]=a; w[2*i-1]=b;
        tot += a+b;
    }
    cur=meh(1, 0); dfs(1, 0); ans[1]=tot-ans[1];
    memset(dist,-1,sizeof(dist));
    q.push({1, 0});
    while(q.size()){
        auto t = q.top(); q.pop();
        if(dist[t.first]!=-1) continue;
        dist[t.first]=t.second; b = t.first;
        for(auto v : adj[t.first]){
            q.push({v.first,w[v.second]+t.second});
        }
    }
    memset(dist,-1,sizeof(dist));
    memset(par,-1,sizeof(par));
    q.push({b,0}); par[b]=0;
    while(q.size()){
        auto t = q.top(); q.pop();
        if(dist[t.first]!=-1) continue;
        dist[t.first]=t.second; a = t.first;
        for(auto v : adj[t.first]){
            q.push({v.first,w[v.second]+t.second});
            if(par[v.first]==-1) par[v.first]=t.first;
        }
    }
    ll lst = -1; cur = 0;
    while(a){
        for(auto v : adj[a]){
            if(v.first==lst||v.first==par[a])
                cur += w[v.second^1];
            else{
                cur += meh(v.first, a)+w[v.second^1];
                auto tmp = dfs2(v.first, a);
                tmp.second += w[v.second];
                ord.push_back(tmp);
            }
        }
        lst = a; a = par[a];
    }
    sort(ord.begin(),ord.end(),[](pair<ll,ll>i,pair<ll,ll>j){return i.second>j.second;});
    ans[2] = tot - cur;
    for(i=0;i<ord.size();i++){
        ans[3+i]=ans[2+i]-ord[i].second;
    }
    for(i=1;i<=N;i++){if(ans[i]==-1) ans[i]=ans[i-1];}
    for(scanf("%lld",&Q);Q;Q--){
        scanf("%lld",&x);
        printf("%lld\n",ans[x]);
    }
    return 0;
}

Compilation message (stderr)

designated_cities.cpp: In function 'int main()':
designated_cities.cpp:85:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(i=0;i<ord.size();i++){
             ~^~~~~~~~~~~
designated_cities.cpp:39:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(scanf("%lld",&N),i=1;i<N;i++){
         ~~~~~~~~~~~~~~~~^~~~
designated_cities.cpp:40:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld%lld%lld%lld",&x,&y,&a,&b);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
designated_cities.cpp:89:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(scanf("%lld",&Q);Q;Q--){
         ~~~~~^~~~~~~~~~~
designated_cities.cpp:90:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld",&x);
         ~~~~~^~~~~~~~~~~

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