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Submission #948693

# Submission time Handle Problem Language Result Execution time Memory
948693 2024-03-18T11:19:17 Z GrindMachine Mousetrap (CEOI17_mousetrap) C++17
45 / 100
 812 ms 60492 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 1e6 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

vector<int> adj[N];
vector<int> dp(N);

void dfs1(int u, int p){
    int deg = sz(adj[u])-(p != -1);
    dp[u] = deg;
    vector<int> vals;
    vals.pb(0), vals.pb(0);

    trav(v,adj[u]){
        if(v == p) conts;
        dfs1(v,u);
        vals.pb(dp[v]);
    }

    sort(rall(vals));
    dp[u] += vals[1];
}

vector<int> curr_path;
vector<int> path;

void dfs2(int u, int p, int des){
    curr_path.pb(u);
    if(u == des){
        path = curr_path;
    }

    trav(v,adj[u]){
        if(v == p) conts;
        dfs2(v,u,des);
    }

    curr_path.pop_back();
}

void solve(int test_case)
{
    int n,t,m; cin >> n >> t >> m;
    rep1(i,n-1){
        int u,v; cin >> u >> v;
        adj[u].pb(v), adj[v].pb(u);
    }

    dfs1(m,-1);
    dfs2(m,-1,t);
    path.pop_back();

    vector<bool> on_path(n+5);
    trav(u,path) on_path[u] = 1;
    int moves = 0;
    int ans = 0;

    rep(i,sz(path)){
        int u = path[i];
        int deg = sz(adj[u])-(u != m)-1;
        ans += deg;
    }

    auto ok = [&](int mid){
        int moves = 0;
        rep(i,sz(path)){
            int u = path[i];
            moves++;

            vector<int> vals;
            trav(v,adj[u]){
                if(on_path[v]) conts;
                vals.pb(dp[v]);
            }
            
            trav(x,vals){
                if(x > mid){
                    moves--;
                }
            }

            if(moves < 0) return false;
        }

        return true;
    };

    int l = 0, r = n;
    int mn_add = -1;

    while(l <= r){
        int mid = (l+r) >> 1;
        if(ok(mid)){
            mn_add = mid;
            r = mid-1;
        }
        else{
            l = mid+1;
        }
    }

    assert(mn_add != -1);
    ans += mn_add;

    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Compilation message

mousetrap.cpp: In function 'void solve(int)':
mousetrap.cpp:110:9: warning: unused variable 'moves' [-Wunused-variable]
  110 |     int moves = 0;
      |         ^~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 27740 KB Output is correct
2 Correct 7 ms 27740 KB Output is correct
3 Correct 7 ms 27736 KB Output is correct
4 Correct 7 ms 27740 KB Output is correct
5 Correct 7 ms 27740 KB Output is correct
6 Correct 7 ms 27772 KB Output is correct
7 Correct 7 ms 27740 KB Output is correct
8 Correct 7 ms 27740 KB Output is correct
9 Correct 6 ms 27740 KB Output is correct
10 Correct 7 ms 27736 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 279 ms 59248 KB Output is correct
2 Correct 244 ms 55908 KB Output is correct
3 Correct 812 ms 60492 KB Output is correct
4 Correct 327 ms 44116 KB Output is correct
5 Correct 784 ms 60264 KB Output is correct
6 Correct 761 ms 60264 KB Output is correct

Subtask #3
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 27740 KB Output is correct
2 Correct 7 ms 27740 KB Output is correct
3 Correct 7 ms 27736 KB Output is correct
4 Correct 7 ms 27740 KB Output is correct
5 Correct 7 ms 27740 KB Output is correct
6 Correct 7 ms 27772 KB Output is correct
7 Correct 7 ms 27740 KB Output is correct
8 Correct 7 ms 27740 KB Output is correct
9 Correct 6 ms 27740 KB Output is correct
10 Correct 7 ms 27736 KB Output is correct
11 Correct 7 ms 27740 KB Output is correct
12 Correct 7 ms 27872 KB Output is correct
13 Correct 7 ms 27740 KB Output is correct
14 Correct 8 ms 27868 KB Output is correct
15 Correct 7 ms 27996 KB Output is correct
16 Incorrect 8 ms 27780 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #4
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 27740 KB Output is correct
2 Correct 7 ms 27740 KB Output is correct
3 Correct 7 ms 27736 KB Output is correct
4 Correct 7 ms 27740 KB Output is correct
5 Correct 7 ms 27740 KB Output is correct
6 Correct 7 ms 27772 KB Output is correct
7 Correct 7 ms 27740 KB Output is correct
8 Correct 7 ms 27740 KB Output is correct
9 Correct 6 ms 27740 KB Output is correct
10 Correct 7 ms 27736 KB Output is correct
11 Correct 279 ms 59248 KB Output is correct
12 Correct 244 ms 55908 KB Output is correct
13 Correct 812 ms 60492 KB Output is correct
14 Correct 327 ms 44116 KB Output is correct
15 Correct 784 ms 60264 KB Output is correct
16 Correct 761 ms 60264 KB Output is correct
17 Correct 7 ms 27740 KB Output is correct
18 Correct 7 ms 27872 KB Output is correct
19 Correct 7 ms 27740 KB Output is correct
20 Correct 8 ms 27868 KB Output is correct
21 Correct 7 ms 27996 KB Output is correct
22 Incorrect 8 ms 27780 KB Output isn't correct
23 Halted 0 ms 0 KB -