oj.uz

Submission #1094186

# Submission time Handle Problem Language Result Execution time Memory
1094186 2024-09-28T21:43:24 Z stefanopulos Cat Exercise (JOI23_ho_t4) C++17
0 / 100
 4 ms 5212 KB 
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>
 
using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ldb;
 
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ldb,ldb> pdd;

#define ff(i,a,b) for(int i = a; i <= b; i++)
#define fb(i,b,a) for(int i = b; i >= a; i--)
#define trav(a,x) for(auto& a : x)
 
#define sz(a) (int)(a).size()
#define fi first
#define se second
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

// os.order_of_key(k) the number of elements in the os less than k
// *os.find_by_order(k)  print the k-th smallest number in os(0-based)

const int mod = 1000000007;
const int inf = 1e9 + 5;
const int mxN = 200005; 

int n;
int niz[mxN];

vector<int> g[mxN];

int id[mxN];
bool cmp(int i, int j){
    return niz[i] < niz[j];
}

int d[mxN];
int deda[mxN][20];
void dfs(int v, int p){
    deda[v][0] = p;
    ff(i,1,19)deda[v][i] = deda[deda[v][i - 1]][i - 1];
    
    for(auto u : g[v]){
        if(u != p){
            d[u] = d[v] + 1;
            dfs(u, v);
        }
    }

}

int LCA(int x, int y){
    if(d[x] < d[y])swap(x, y);
    fb(i,19,0)if((d[x] - d[y]) & (1 << i))x = deda[x][i];
    fb(i,19,0)if(deda[x][i] != deda[y][i])x = deda[x][i], y = deda[y][i];
    return (x == y ? x : deda[x][0]);
}

int dist(int x, int y){
    return d[x] + d[y] - 2 * d[LCA(x, y)];
}

ll sum[mxN];
int par[mxN];
int findpar(int x){
    return (x == par[x] ? x : par[x] = findpar(par[x]));
}
void unite(int x, int y){
    x = findpar(x), y = findpar(y);
    par[y] = x;
}

int main(){
    cin.tie(0)->sync_with_stdio(0);

    cin >> n;
    ff(i,1,n)cin >> niz[i];
    ff(i,1,n - 1){
        int u, v;
        cin >> u >> v;
        g[u].pb(v);
        g[v].pb(u);
    }

    dfs(1, 0);

    ff(i,1,n)id[i] = i;
    sort(id + 1, id + n + 1, cmp);

    ff(i,1,n)par[i] = i;

    ff(i,1,n){
        int v = id[i];

        int mx = 0;
        for(auto c : g[v]){
            if(niz[c] < niz[v]){
                int a = findpar(c);

                if(sum[a] + dist(a, v) > sum[v]){
                    sum[v] = sum[a] + dist(a, v);
                    mx = a;
                }

            }
        }

        if(mx > 0)unite(v, mx);

    }

    cout << sum[id[n]] << '\n';

    return 0;
}
/*



// probati bojenje sahovski
*/

Subtask #1
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4956 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4952 KB Output is correct
4 Correct 4 ms 5160 KB Output is correct
5 Correct 2 ms 4956 KB Output is correct
6 Incorrect 2 ms 4956 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #2
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4956 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4952 KB Output is correct
4 Correct 4 ms 5160 KB Output is correct
5 Correct 2 ms 4956 KB Output is correct
6 Incorrect 2 ms 4956 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4956 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4952 KB Output is correct
4 Correct 4 ms 5160 KB Output is correct
5 Correct 2 ms 4956 KB Output is correct
6 Incorrect 2 ms 4956 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4956 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4952 KB Output is correct
4 Correct 4 ms 5160 KB Output is correct
5 Correct 2 ms 4956 KB Output is correct
6 Incorrect 2 ms 4956 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4956 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4952 KB Output is correct
4 Correct 4 ms 5160 KB Output is correct
5 Correct 2 ms 4956 KB Output is correct
6 Incorrect 2 ms 4956 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #6
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4952 KB Output is correct
2 Incorrect 3 ms 5212 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #7
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4956 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4952 KB Output is correct
4 Correct 4 ms 5160 KB Output is correct
5 Correct 2 ms 4956 KB Output is correct
6 Incorrect 2 ms 4956 KB Output isn't correct
7 Halted 0 ms 0 KB -