oj.uz

Submission #701167

# Submission time Handle Problem Language Result Execution time Memory
701167 2023-02-20T09:40:34 Z Do_you_copy Zagrade (COI17_zagrade) C++17
100 / 100
 1220 ms 47996 KB 
#include <bits/stdc++.h>
#define fi first
#define se second
#define faster ios_base::sync_with_stdio(0); cin.tie(0);
#define pb push_back

using namespace std;
using ll = long long;
using pii = pair <int, int>;

const int maxN = 3e5 + 100;
const int inf = 0x3f3f3f3f;
//const int Mod =
string s;
int n;
bool visited[maxN];
int sz[maxN];
int cnt[maxN];
vector <int> adj[maxN];
int a[maxN];
void pre_dfs(int u, int p){
    sz[u] = 1;
    for (int i: adj[u]){
        if (i == p || visited[i]) continue;
        pre_dfs(i, u);
        sz[u] += sz[i];
    }
}

int find_cent(int u, int p, int szz){
    for (int i: adj[u]){
        if (i == p || visited[i]) continue;
        if (sz[i] > szz / 2) return find_cent(i, u, szz);
    }
    return u;
}

ll ans = 0;
void dfs(int u, int p, int t, int d, int minn){
    //t == 0: calculate
    //t == 1: add
    //t == 2: delete
    if (t == 0){
        minn = min(minn, d);
        //if (u == 4 && p == 2) cerr << d << " " << minn << "\n";
        if (minn == d){
            ans += cnt[-minn];
        }
    }
    if (t == 1){
        minn = min(minn + a[u], a[u]);
        if (minn >= 0) ++cnt[d];
    }
    if (t == 2){
        minn = min(minn + a[u], a[u]);
        if (minn >= 0) --cnt[d];
    }
    for (int i: adj[u]){
        if (i == p || visited[i]) continue;
        dfs(i, u, t, d + a[i], minn);
    }
}

void update(int u){
    //if (u == 2) cerr << a[4] << ":D";
    if (a[u] == 1) cnt[1] = 1;
    for (int i: adj[u]){
        if (visited[i]) continue;
        dfs(i, u, 0, a[i], 0);
        dfs(i, u, 1, a[u] + a[i], a[u]);
    }
    for (int i: adj[u]){
        if (visited[i]) continue;
        dfs(i, u, 2, a[u] + a[i], a[u]);
    }
    if (a[u] == 1) cnt[1] = 0;
}

void build_cent(int u){
    pre_dfs(u, u);
    int cent = find_cent(u, u, sz[u]);
    //cerr << cent << "\n";
    visited[cent] = 1;
    update(cent);
    for (int i: adj[cent]){
        if (visited[i]) continue;
        build_cent(i);
    }
}

void Init(){
    cin >> n;
    cin >> s;
    s = " " + s;
    for (int i = 1; i <= n; ++i){
        if (s[i] == '(') a[i] = 1;
        else a[i] = -1;
    }
    for (int i = 1; i < n; ++i){
        int u, v;
        cin >> u >> v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
    build_cent(1);
    fill(visited + 1, visited + 1 + n, 0);
    for (int i = 1; i <= n; ++i) a[i] = -a[i];
    build_cent(1);
    cout << ans;

}

#define taskname "test"
signed main(){
    faster
    if (fopen(taskname ".inp", "r")){
        freopen(taskname ".inp", "r", stdin);
        freopen(taskname ".out", "w", stdout);
    }
    int tt = 1;
    //cin >> tt;
    while (tt--){
        Init();
    }
    if (fopen("timeout.txt", "r")){
        ofstream timeout("timeout.txt");
        cerr << "Time elapsed: " << signed(double(clock()) / CLOCKS_PER_SEC * 1000) << "ms\n";
        timeout << signed(double(clock()) / CLOCKS_PER_SEC * 1000);
        timeout.close();
    }
}

Compilation message

zagrade.cpp: In function 'int main()':
zagrade.cpp:117:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  117 |         freopen(taskname ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
zagrade.cpp:118:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  118 |         freopen(taskname ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 7412 KB Output is correct
2 Correct 5 ms 7380 KB Output is correct
3 Correct 5 ms 7436 KB Output is correct
4 Correct 5 ms 7388 KB Output is correct
5 Correct 5 ms 7380 KB Output is correct
6 Correct 4 ms 7396 KB Output is correct
7 Correct 5 ms 7380 KB Output is correct
8 Correct 5 ms 7380 KB Output is correct
9 Correct 6 ms 7380 KB Output is correct
10 Correct 6 ms 7384 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 577 ms 47380 KB Output is correct
2 Correct 540 ms 47680 KB Output is correct
3 Correct 516 ms 47376 KB Output is correct
4 Correct 546 ms 47556 KB Output is correct
5 Correct 528 ms 47352 KB Output is correct
6 Correct 529 ms 47460 KB Output is correct
7 Correct 524 ms 47332 KB Output is correct
8 Correct 534 ms 47588 KB Output is correct
9 Correct 527 ms 47380 KB Output is correct
10 Correct 556 ms 47996 KB Output is correct
11 Correct 491 ms 47372 KB Output is correct

Subtask #3
60.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 7412 KB Output is correct
2 Correct 5 ms 7380 KB Output is correct
3 Correct 5 ms 7436 KB Output is correct
4 Correct 5 ms 7388 KB Output is correct
5 Correct 5 ms 7380 KB Output is correct
6 Correct 4 ms 7396 KB Output is correct
7 Correct 5 ms 7380 KB Output is correct
8 Correct 5 ms 7380 KB Output is correct
9 Correct 6 ms 7380 KB Output is correct
10 Correct 6 ms 7384 KB Output is correct
11 Correct 577 ms 47380 KB Output is correct
12 Correct 540 ms 47680 KB Output is correct
13 Correct 516 ms 47376 KB Output is correct
14 Correct 546 ms 47556 KB Output is correct
15 Correct 528 ms 47352 KB Output is correct
16 Correct 529 ms 47460 KB Output is correct
17 Correct 524 ms 47332 KB Output is correct
18 Correct 534 ms 47588 KB Output is correct
19 Correct 527 ms 47380 KB Output is correct
20 Correct 556 ms 47996 KB Output is correct
21 Correct 491 ms 47372 KB Output is correct
22 Correct 1220 ms 24072 KB Output is correct
23 Correct 1095 ms 24080 KB Output is correct
24 Correct 1147 ms 24080 KB Output is correct
25 Correct 1207 ms 24076 KB Output is correct
26 Correct 692 ms 31712 KB Output is correct
27 Correct 696 ms 28280 KB Output is correct
28 Correct 702 ms 26964 KB Output is correct
29 Correct 519 ms 47860 KB Output is correct
30 Correct 502 ms 47908 KB Output is correct
31 Correct 85 ms 23692 KB Output is correct
32 Correct 534 ms 47384 KB Output is correct