Submission #583845

#	Time	Username	Problem	Language	Result	Execution time	Memory
583845		thezomb1e	Regions (IOI09_regions)	C++17	100 / 100	7614 ms	113248 KiB

regions

//thatsramen

#include <bits/stdc++.h>
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define eb emplace_back
#define pb push_back
#define ft first
#define sd second
#define pi pair<int, int>
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define dbg(...) dbg_out(__VA_ARGS__)

using ll = long long;
using ld = long double;
using namespace std;
using namespace __gnu_pbds;

//Constants
const ll INF = 5 * 1e18;
const int IINF = 2 * 1e9;
const ll MOD = 1e9 + 7;
// const ll MOD = 998244353;
const ll dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
const ld PI = 3.14159265359;

//Templates
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) {return os << '(' << p.first << ", " << p.second << ')';}
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) {os << '['; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << ']';}
void dbg_out() {cerr << endl;}
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cerr << H << ' '; dbg_out(T...); }
template<typename T> void mins(T& x, T y) {x = min(x, y);}
template<typename T> void maxs(T& x, T y) {x = max(x, y);}
template<typename T> using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T> using omset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

//order_of_key(k): number of elements strictly less than k
//find_by_order(k): k-th element in the set

void setPrec() {cout << fixed << setprecision(15);}
void unsyncIO() {cin.tie(0)->sync_with_stdio(0);}
void setIn(string s) {freopen(s.c_str(), "r", stdin);}
void setOut(string s) {freopen(s.c_str(), "w", stdout);}
void setIO(string s = "") {
    unsyncIO(); setPrec();
    if(s.size()) setIn(s + ".in"), setOut(s + ".out");
}

// #define TEST_CASES

struct SegmentTree {
    
    vector<vector<int>> tre;
    int sz;
    
    SegmentTree(vector<int> &a) {
        int n = (int) a.size();
        sz = 1;
        while (sz < n) sz *= 2;
        tre.resize(2 * sz);
        build(a, 1, 0, sz);
    }

    vector<int> op(vector<int> &a, vector<int> &b) {
        vector<int> res;
        int n = a.size(), m = b.size();
        int i = 0, j = 0;
        while (i < n || j < m) {
            if (j == m || (i < n && a[i] < b[j])) {
                res.pb(a[i++]);
            } else {
                res.pb(b[j++]);
            }
        }
        return res;
    }

    void rcl(int x) {
        tre[x] = op(tre[2 * x], tre[2 * x + 1]);
    }

    void build(vector<int> &a, int x, int lx, int rx) {
        if (rx - lx == 1) {
            if (lx < a.size()) {
                tre[x] = {a[lx]};
            }
            return;
        }
        int m = (lx + rx) / 2;
        build(a, 2 * x, lx, m);
        build(a, 2 * x + 1, m, rx);
        rcl(x);
    }

    int get(int l, int r, int bb, int x, int lx, int rx) {
        if (rx <= l || lx >= r) {
            return 0;
        }
        if (l <= lx && r >= rx) {
            int lo = 0, hi = (int) tre[x].size() - 1;
            int res = -1;
            while (lo <= hi) {
                int mi = (lo + hi) / 2;
                if (tre[x][mi] <= bb) {
                    res = mi;
                    lo = mi + 1;
                } else {
                    hi = mi - 1;
                }
            }
            return res + 1;
        }
        int m = (lx + rx) / 2;
        int s1 = get(l, r, bb, 2 * x, lx, m);
        int s2 = get(l, r, bb, 2 * x + 1, m, rx);
        return s1 + s2;
    }

    int get(int l, int r, int bb) {
        return get(l, r, bb, 1, 0, sz);
    }
};

const int MAX = 1000 * 1000 * 1000;
const int sq = 420;

void solve() {
    int n, r, q;
    cin >> n >> r >> q;
    vector<vector<int>> e(n + 5);
    vector<int> region(n + 5), cnt(r + 5, 0);
    cin >> region[1];
    for (int i = 2; i <= n; i++) {
        int p; cin >> p;
        e[p].pb(i);
        cin >> region[i];
        cnt[region[i]]++;
    }
    vector<int> fun(r + 5, 0);
    int pp = 1;
    for (int i = 1; i <= r; i++) {
        if (cnt[i] > sq) fun[i] = pp++;
    }
    vector<int> up_cnt(pp + 2, 0);
    vector<vector<int>> pre(pp + 2, vector<int> (n + 5, 0));
    vector<vector<pi>> init(r + 5);
    int time = 0; 
    function<void(int)> dfs = [&](int f) {
        int reg = region[f];
        for (int i = 1; i < pp; i++) {
            if (pre[i][reg] <= MAX)
                pre[i][reg] += up_cnt[i];
        }
        up_cnt[fun[reg]]++;
        pi cur; cur.ft = time++;
        for (int to : e[f]) {
            dfs(to);
        }
        cur.sd = time++;
        init[reg].pb(cur);
        up_cnt[fun[reg]]--;
    };
    dfs(1);
    vector<SegmentTree> sts;
    for (int i = 1; i <= r; i++) {
        sort(all(init[i]));
        vector<int> tru; 
        for (pi x : init[i]) tru.pb(x.sd);
        sts.pb(SegmentTree(tru));
    }
    for (int i = 0; i < q; i++) {
        int r1, r2; 
        cin >> r1 >> r2;
        if (cnt[r1] > sq) {
            cout << pre[fun[r1]][r2] << endl;
        } else {
            int ans = 0;
            if (!init[r2].empty()) {
                for (pi x : init[r1]) {
                    pi val = {x.ft, -IINF};
                    int j = lower_bound(all(init[r2]), val) - init[r2].begin();
                    ans += sts[r2 - 1].get(j, (int) init[r2].size(), x.sd);
                }
            }
            cout << ans << endl;
        }
    }
}

int main() {
    setIO();

    int tt = 1;
    #ifdef TEST_CASES
        cin >> tt;
    #endif

    while (tt--)
        solve();

    return 0;
}

Compilation message (stderr)

regions.cpp:5: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    5 | #pragma GCC optimization ("O3")
      | 
regions.cpp:6: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    6 | #pragma GCC optimization ("unroll-loops")
      | 
regions.cpp: In member function 'void SegmentTree::build(std::vector<int>&, int, int, int)':
regions.cpp:89:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   89 |             if (lx < a.size()) {
      |                 ~~~^~~~~~~~~~
regions.cpp: In function 'void setIn(std::string)':
regions.cpp:47:30: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 | void setIn(string s) {freopen(s.c_str(), "r", stdin);}
      |                       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
regions.cpp: In function 'void setOut(std::string)':
regions.cpp:48:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 | void setOut(string s) {freopen(s.c_str(), "w", stdout);}
      |                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 85 / 85