oj.uz

Submission #577102

# Submission time Handle Problem Language Result Execution time Memory
577102 2022-06-14T04:48:14 Z talant117408 Wells (CEOI21_wells) C++17
0 / 100
 18 ms 35540 KB 
#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;

#define long                unsigned long 
#define pb                  push_back
#define mp                  make_pair
#define all(v)              (v).begin(),(v).end()
#define rall(v)             (v).rbegin(),(v).rend()
#define lb                  lower_bound
#define ub                  upper_bound
#define sz(v)               int((v).size())
#define do_not_disturb      ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define endl                '\n'

const int N = 1500007;
vector <int> graph[N];
int well[N], depth[N], n, k;
bool flag;

void dfs(int v = 1, int p = 1) {
    for (auto to : graph[v]) {
        if (to == p) continue;
        depth[to] = depth[v] + 1;
        dfs(to, v);
    }
}

int find_wells(int v = 1, int p = 1) {
    vector <int> depths;
    for (auto to : graph[v]) {
        if (to == p) continue;
        auto res = find_wells(to, v);
        if (res) {
            depths.pb(res);
        }
    }
    sort(rall(depths));
    if ((sz(depths) && depths[0] >= k-1) || (sz(depths) > 1 && depths[0]+depths[1] >= k-1)) {
        well[v] = 1;
        return 0;
    }
    if (sz(depths)) return depths[0]+1;
    else return 1;
}

int find_dbw(int v = 1, int p = 1) {
    vector <int> depths;
    for (auto to : graph[v]) {
        if (to == p) continue;
        auto res = find_dbw(to, v);
        if (res) {
            depths.pb(res);
        }
    }
    sort(all(depths));
    if ((well[v] && sz(depths) && depths[0] < k) || (sz(depths) > 1 && depths[0]+depths[1] < k)) {
        cout << "NO\n0";
        exit(0);
    }
    if (well[v]) return 1;
    else if (sz(depths)) return depths[0]+1;
    else return 0;
}

void solve() {
    cin >> n >> k;
    for (int i = 1; i < n; i++) {
        int a, b;
        cin >> a >> b;
        graph[a].pb(b);
        graph[b].pb(a); 
    }
    dfs();
    find_wells();
    find_dbw(); // distance between wells
    if (flag) cout << "NO\0";
    else cout << "YES\n1";
}

int main() {
    do_not_disturb
    
    int t = 1;
    //~ cin >> t;
    while (t--) {
        solve();
    }
    
    return 0;
}

Subtask #1
0.0 / 30.0

# Verdict Execution time Memory Grader output
1 Partially correct 18 ms 35540 KB Output is partially correct
2 Incorrect 17 ms 35540 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
0.0 / 20.0

# Verdict Execution time Memory Grader output
1 Partially correct 18 ms 35540 KB Output is partially correct
2 Incorrect 17 ms 35540 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
0.0 / 20.0

# Verdict Execution time Memory Grader output
1 Partially correct 18 ms 35540 KB Output is partially correct
2 Incorrect 17 ms 35540 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0.0 / 30.0

# Verdict Execution time Memory Grader output
1 Partially correct 18 ms 35540 KB Output is partially correct
2 Incorrect 17 ms 35540 KB Output isn't correct
3 Halted 0 ms 0 KB -