Submission #1036459

#	Time	Username	Problem	Language	Result	Execution time	Memory
1036459		MarwenElarbi	Chase (CEOI17_chase)	C++17	100 / 100	166 ms	180560 KiB

chase

#include <bits/stdc++.h>
#define vi vector<int>
#define ve vector
#define ll long long
#define vl vector<ll>
#define vll vector<pair<ll,ll>>
#define onbit __builtin_popcount
#define ii pair<int,int>
#define vvi vector<vi>
#define vii vector<ii>
#define gii greater<ii>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define INF 1e18
#define eps 1e-7
#define eps1 1e-2
#define optimise ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define MAX_A 1e5+5
using namespace std;
const int MOD = 1e9+7;
const int nax = 2e5+5;
const int MAX_VAL = 1e6;
double PI=3.14159265359;
int arx[8]={1,1,0,-1,-1,-1, 0, 1};
int ary[8]={0,1,1, 1, 0,-1,-1,-1};
typedef complex<int> Point;
#define X real()
#define Y imag()
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
vector<int> adj[nax];
ll sum[nax];
int tab[nax];
ll dp[nax][102][2];
ll cur[102][2];
int n,k;
ll ans;
void dfs(int x,int p){
    dp[x][1][0]=sum[x];
    for(auto u:adj[x]){
        if(u==p) continue;
        dfs(u,x);
        for (int i = 1; i <= k; ++i)
        {
            ll down=max(dp[u][i][0],dp[u][i-1][0]+sum[x]-tab[u]);
            ll up=max(dp[u][i][1],dp[u][i-1][1]+sum[u]-tab[x]);
            cur[i][0]=down;
            cur[i][1]=up;
            if(i!=k){
                ans=max(ans,max(dp[x][k-i][0]+up,dp[x][k-i][1]+down));
                ans=max(ans,dp[u][i][1]+sum[x]);
            }
        }
        for (int i = 1; i <= k; ++i)
        {
            dp[x][i][0]=max(dp[x][i][0],cur[i][0]);
            dp[x][i][1]=max(dp[x][i][1],cur[i][1]);
            ans=max(ans,dp[x][i][0]);
        }
    }
    return;
}
int main(){
    optimise;
    //setIO("closing");
    cin>>n>>k;
    for (int i = 0; i < n; ++i)
    {
        cin>>tab[i];
    }
    for (int i = 0; i < n-1; ++i)
    {
        int x,y;
        cin>>x>>y;
        x--;y--;
        sum[x]+=tab[y];
        sum[y]+=tab[x];
        adj[x].pb(y);
        adj[y].pb(x);
    }
    if(!k){
        cout << 0<<endl;
        return 0;
    }
    dfs(0,-1);
    cout <<ans<<endl;
}   

Compilation message (stderr)

chase.cpp: In function 'void setIO(std::string)':
chase.cpp:32:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
chase.cpp:33:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 30 / 30