oj.uz

Submission #680831

# Submission time Handle Problem Language Result Execution time Memory
680831 2023-01-11T20:56:02 Z sysia Mousetrap (CEOI17_mousetrap) C++17
100 / 100
 794 ms 240824 KB 
//Sylwia Sapkowska
#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;

void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef LOCAL
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

#define int long long
typedef pair<int, int> T;
const int oo = 1e18, oo2 = 1e9+7, K = 30;
const int mod = 998244353;

void solve(){
    int n, t, m;
    cin >> n >> t >> m;
    vector<vector<int>>g(n+1);
    for (int i = 1; i<n; i++){
        int a, b; cin >> a >> b;
        g[a].emplace_back(b);
        g[b].emplace_back(a);
    }
    vector<int>dp(n+1), par(n+1);
    function<void(int, int)>dfs = [&](int v, int pa){
        par[v] = pa;
        int mx = 0, mx2 = 0;
        for (auto x: g[v]){
            if (x == pa) continue;
            dfs(x, v);
            if (dp[x] >= mx){
                mx2 = mx;
                mx = dp[x];
            } else if (dp[x] >= mx2) {
                mx2 = dp[x];
            }
        }
        dp[v] = (int)g[v].size() - (v == t ? 0 : 1) + mx2;
    };
    dfs(t, t);
    debug(dp);
    int u = m;
    vector<int>path(n+1);
    while (1){
        path[u] = 1;
        if (u == par[u]) break;
        u = par[u];
    }
    vector<int>deg(n+1);
    for (int i = 1; i<=n; i++){
        for (auto x: g[i]){
            if (par[x] == i && !path[x]){
                deg[i]++; //ile wierzcholkow zbacza
            }
        }
    }
    auto check = [&](int mid){
        int v = m;
        int sum = 0;
        while (1){
            sum += deg[v];
            v = par[v];
            if (v == par[v]) break;
        }
        if (sum > mid) return false;
        v = m;
        int block = 0, need = 0;
        while (1){
            block++;
            int dont_care = 0;
            //rozwazyc zboczenie w dol w v
            for (auto x: g[v]){
                if (path[x]) continue;
                if (dp[x] + sum > mid) need++;
                else dont_care++;
            }
            sum -= dont_care; //slonik will win in mid moves anyway
            if (block < need) return false;
            v = par[v];
            if (v == par[v]) break;
        }
        return true;
    };
    int L = 0, R = 2*n, ans = 2*n;
    while (R >= L){
        int mid = (L+R)/2;
        if (check(mid)) {
            ans = mid;
            R = mid-1;
        } else {
            L = mid+1;
        }
    }
    cout << ans << "\n";
}

int32_t main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int t = 1;
    // cin >> t;
    while (t--) solve();

    return 0;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 324 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 320 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 279 ms 94176 KB Output is correct
2 Correct 247 ms 84852 KB Output is correct
3 Correct 713 ms 92628 KB Output is correct
4 Correct 336 ms 46364 KB Output is correct
5 Correct 712 ms 92500 KB Output is correct
6 Correct 713 ms 92504 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 324 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 320 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 ms 328 KB Output is correct
19 Correct 1 ms 328 KB Output is correct
20 Correct 1 ms 340 KB Output is correct
21 Correct 1 ms 340 KB Output is correct
22 Correct 1 ms 340 KB Output is correct

Subtask #4
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 324 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 320 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 279 ms 94176 KB Output is correct
12 Correct 247 ms 84852 KB Output is correct
13 Correct 713 ms 92628 KB Output is correct
14 Correct 336 ms 46364 KB Output is correct
15 Correct 712 ms 92500 KB Output is correct
16 Correct 713 ms 92504 KB Output is correct
17 Correct 0 ms 212 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 1 ms 340 KB Output is correct
20 Correct 1 ms 468 KB Output is correct
21 Correct 1 ms 468 KB Output is correct
22 Correct 1 ms 340 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 1 ms 328 KB Output is correct
25 Correct 1 ms 328 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 1 ms 340 KB Output is correct
28 Correct 1 ms 340 KB Output is correct
29 Correct 1 ms 212 KB Output is correct
30 Correct 289 ms 107640 KB Output is correct
31 Correct 298 ms 107660 KB Output is correct
32 Correct 465 ms 240816 KB Output is correct
33 Correct 346 ms 240824 KB Output is correct
34 Correct 746 ms 105640 KB Output is correct
35 Correct 735 ms 105696 KB Output is correct
36 Correct 784 ms 119756 KB Output is correct
37 Correct 794 ms 119760 KB Output is correct
38 Correct 650 ms 124164 KB Output is correct
39 Correct 618 ms 124224 KB Output is correct
40 Correct 635 ms 124172 KB Output is correct