Submission #1275442

#	Time	Username	Problem	Language	Result	Execution time	Memory
1275442		vibeduck	Jobs (BOI24_jobs)	C++20	0 / 100	1 ms	572 KiB

Main

#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define int long long
#define all(x) (x).begin(), (x).end()

typedef long double ld;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<vector<int>> vvi;
typedef vector<vector<bool>> vvb;
typedef vector<vector<ll>> vvll;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef map<int, int> mii;
typedef unordered_map<int, int> umii;

const int mod = 1e9 + 7;
const int inf = INTMAX_MAX;
const bool tc = false;

int n, s, ans = 0;
const int mxn = 2002;
int p[mxn], x[mxn]; vi adj[mxn];

pii calc = {-2e18, 0};
pii df = calc;
int cnode = -1;

void dfs(int u, int c, int mx) {
    c += x[u]; mx = min(mx, c);

    //cout << u << " " << c << " " << mx << '\n';

    if (c > 0) {
        if (mx > calc.fi) {
            cnode = u;
            calc = mp(mx, c);
        }
        return;
    }

    for (auto &v : adj[u]) {
        if (v == p[u]) continue;
        dfs(v, c, mx);
    }
}

pair<pii, pii> calculate(int root) {
    calc = df;
    cnode = -1;
    dfs(root, 0, 0);
    return {calc, {root, cnode}};
}

void reset(int u, int r) {
    while (u != r) {
        x[u] = 0;
        u = p[u];
    }
    x[r] = 0;
}

inline void solve() {
    cin >> n >> s;
    assert(n <= 1000);
    for (int i = 0; i < n; i++) {
        cin >> x[i] >> p[i];
        p[i]--;
        if (p[i] != -1) {
            adj[i].pb(p[i]);
            adj[p[i]].pb(i);
        }
    }

    priority_queue<pair<pii, pii>> st;
    for (int i = 0; i < n; i++) {
        if (p[i] != -1) continue;
        pair<pii, pii> c = calculate(i);
        if (c.fi != df) st.push(c);
    }

    // {mx, c, root, u}

    while (st.size()) {
        //cout << st.size() << '\n';
        auto cur = st.top();
        st.pop();
        if (s + cur.fi.fi < 0) break;
        ans += cur.fi.se;
        s += cur.fi.se;
        reset(cur.se.se, cur.se.fi);
        //cout << cur.se.fi << '\n';
        pair<pii, pii> c = calculate(cur.se.fi);
        //cout << c.fi.fi << " " << df.fi << '\n';
        if (c.fi.fi != df.fi) st.push(c);
    }

    cout << ans << '\n';
}

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

signed main() {
    ios::sync_with_stdio(false);
    cout.tie(0);
    cin.tie(0);
    //setIO();

    int t = 1;
    if (tc) {
        cin >> t;
    }

    while (t--) {
        solve();
    }
}

Compilation message (stderr)

Main.cpp: In function 'void setIO(std::string)':
Main.cpp:114:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  114 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:115:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  115 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 11
• Subtask 2: 0 / 14
• Subtask 3: 0 / 15
• Subtask 4: 0 / 29
• Subtask 5: 0 / 31