Submission #942277

#	Time	Username	Problem	Language	Result	Execution time	Memory
942277		Ghetto	Homework (CEOI22_homework)	C++17	0 / 100	374 ms	497504 KiB

Main

#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
const int MAX_N = 1e6 + 5;

string str;
int n;

set<int> commas_at_depth[4 * MAX_N]; // Starts at 1
int l[4 * MAX_N], r[4 * MAX_N], d[4 * MAX_N];
int type[4 * MAX_N]; // 1 = min, 2 = max, 3 = leaf
void precomp() {
    for (int i = 0; i < str.size(); i++) n += (bool) (str[i] == '?');

    int depth = 0;
    for (int i = 0; i < str.size(); i++) {
        if (str[i] == '(') depth++;
        else if (str[i] == ')') depth--;
        else if (str[i] == ',') commas_at_depth[depth].insert(i);
    }

    l[1] = 0;
    r[1] = str.size() - 1;
    d[1] = 1;
    for (int i = 1; i <= 4 * n; i++) {
        if (d[i] == 0) continue;
        if (l[i] == r[i]) {
            type[i] = 3;
            continue;
        }

        type[i] = (str[l[i] + 1] == 'i') ? 1 : 2;
        int j = *commas_at_depth[d[i]].lower_bound(l[i]);
        l[2 * i] = l[i] + 4; r[2 * i] = j - 1; d[2 * i] = d[i] + 1;
        l[2 * i + 1] = j + 1; r[2 * i + 1] = r[i] - 1; d[2 * i + 1] = d[i] + 1;
    }

    // for (int i = 1; i <= 4 * n; i++) {
    //     cout << i << ": " << type[i] << endl;
    // }    
}

pii find_bounds(int u) {
    if (type[u] == 3) return {0, 0};

    pii l_bounds = find_bounds(2 * u), r_bounds = find_bounds(2 * u + 1);
    int min_bound = (type[u] == 1) ? min(l_bounds.first, r_bounds.first) : l_bounds.first + r_bounds.first + 1;
    int max_bound = (type[u] == 1) ? l_bounds.second + r_bounds.second + 1 : min(l_bounds.second, r_bounds.second);
    return {min_bound, max_bound};
}

int main() {
    // freopen("homework.in", "r", stdin);

    cin.sync_with_stdio(false);
    cin.tie(0);

    cin >> str;
    precomp();

    pii bounds = find_bounds(1);
    int ans = n - bounds.first - bounds.second;
    cout << ans << '\n';
}

Compilation message (stderr)

Main.cpp: In function 'void precomp()':
Main.cpp:13:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |     for (int i = 0; i < str.size(); i++) n += (bool) (str[i] == '?');
      |                     ~~^~~~~~~~~~~~
Main.cpp:16:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |     for (int i = 0; i < str.size(); i++) {
      |                     ~~^~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 13
• Subtask 3: 0 / 13
• Subtask 4: 0 / 30
• Subtask 5: 0 / 34