Submission #1120004

#	Time	Username	Problem	Language	Result	Execution time	Memory
1120004		yeediot	Designated Cities (JOI19_designated_cities)	C++17	100 / 100	286 ms	33032 KiB

designated_cities

#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=x<y?x:y
#define chmax(x,y) x=x>y?x:y
const int mxn=2e5+5;
inline char gc()
{
    const static int SZ = 1 << 16;
    static char buf[SZ], *p1, *p2;
    if (p1 == p2 && (p2 = buf + fread(p1 = buf, 1, SZ, stdin), p1 == p2))
        return -1;
    return *p1++;
}
inline void rd() {}
template <typename T, typename... U>
inline void rd(T &x, U &...y)
{
    x = 0;
    bool f = 0;
    char c = gc();
    while (isdigit(c))
        x = (x << 1) + (x << 3) + (c ^ 48), c = gc();
    f && (x = -x), rd(y...);
}
template <typename T>
inline void prt(T x)
{
    if (x > 9)
        prt(x / 10);
    putchar((x % 10) ^ 48);
}
vector<array<int,3>>adj[mxn];
ll dp[mxn][2], dep[mxn];
pair<ll,int> dp2[mxn];
int p1;
inline void dfs(int v,int pa){
    for(auto [u,d,d2]:adj[v]){
        if(u==pa)continue;
        dp[u][0]+=dp[v][0]+d;
        dep[u]=dep[v]+d;
        dfs(u,v);
        dp[v][1]+=d2+dp[u][1];
    }
}
ll all,ans[mxn];
inline void calc(int v,int pa){
    ll mx=0;
    dp2[v].F=dep[v];
    dp2[v].S=v;
    int t1=0;
    for(auto [u,d,d2]:adj[v]){
        if(u==pa)continue;
        dp[u][1]+=dp[v][1]-dp[u][1]-d2;
        calc(u,v);
        if(dp2[v].F+dp2[u].F-2*dep[v]>mx){
            t1=dp2[v].S;
            mx=dp2[v].F+dp2[u].F-2*dep[v];
        }
        chmax(dp2[v],dp2[u]);
    }
    chmin(ans[1],all-dp[v][0]-dp[v][1]);
    if(ans[2]>all-dp[v][0]-dp[v][1]-mx){
        p1=t1;
        ans[2]=all-dp[v][0]-dp[v][1]-mx;
    }
}
ll len[mxn];
int idx;
inline ll dfs2(int v,int pa){
    vector<ll>temp;
    for(auto [u,d,d2]:adj[v]){
        if(u==pa)continue;
        temp.pb(dfs2(u,v)+d);
    }
    if(sz(temp)==0)return 0;
    auto it=max_element(temp.begin(),temp.end());
    for(auto it2=temp.begin();it2!=temp.end();it2++){
        if(it2==it)continue;
        len[idx++]=*it2;
    }
    return *it;
}
signed main(){
    int n,q;
    rd(n);
    ans[1] = ans[2]=1e18;
    for(int i=1;i<n;i++){
        int a,b,c,d;
        rd(a),rd(b),rd(c),rd(d);
        adj[a].pb({b,c,d});
        adj[b].pb({a,d,c});
        all+=c+d;
    }
    dfs(1,1);
    calc(1,1);
    ll v=dfs2(p1,p1);
    len[idx++]=v;
    sort(len,len+idx,greater<ll>());
    for(int i=1;i<idx;i++){
        ans[2+i]=ans[1+i]-len[i];
    }
    rd(q);
    while(q--){
        int x;
        rd(x);
        prt(ans[x]);
        putchar('\n');
    }
}
 /*
 input:
 
 */

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