Submission #1087940

#	Time	Username	Problem	Language	Result	Execution time	Memory
1087940		Zero_OP	Regions (IOI09_regions)	C++14	100 / 100	3749 ms	78972 KiB

regions

#include<bits/stdc++.h>

using namespace std;

#define sz(v) (int)v.size()
#define all(v) begin(v), end(v)
#define compact(v) v.erase(unique(all(v)), end(v))
#define dbg(v) "[" #v " = " << (v) << "]"
#define file(name) if(fopen(name".inp", "r")) {freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#define rep(i, l, r) for(int i = (l); i < (r); ++i)

using ll = long long;
using vi = vector<int>;
using vl = vector<long long>;
using ld = long double;

template<typename T> 
    bool minimize(T& a, const T& b){
        if(a > b){
            return a = b, true;
        }  return false;
    }

template<typename T>
    bool maximize(T& a, const T& b){    
        if(a < b){
            return a = b, true;
        } return false;
    }

template<int dimension, typename T>
struct tensor : public vector<tensor<dimension - 1, T>> {
    static_assert(dimension > 0, "Dimension must be positive !\n");
    template<typename... Args>
    tensor(int n = 0, Args... args) : vector<tensor<dimension - 1, T>> (n, tensor<dimension - 1, T>(args...)) {}
};
 
template<typename T>
struct tensor<1, T> : public vector<T> {
    tensor(int n = 0, T val = T()) : vector<T>(n, val) {}
};

const int MAXN = 2e5 + 5;
const int MAXR = 500 * 505;
const int B = 500;

int N, R, Q, H[MAXN], r1[MAXN], r2[MAXN];
vector<int> adj[MAXN];
bool heavy[MAXR];
vector<int> inRegion[MAXR];

int sum[MAXN], target;
ll total_sum[MAXR];

void dfs(int u, vector<ll>& total_sum){
    total_sum[H[u]] += sum[u];
    sum[u] += (H[u] == target);
    for(int v : adj[u]){
        sum[v] = sum[u];
        dfs(v, total_sum);
    }
}

int timerDFS, tin[MAXN], tout[MAXN];
vector<int> pos[MAXR];
vector<ll> save[MAXR];

void init_dfs(int u){
    tin[u] = ++timerDFS;
    pos[H[u]].push_back(tin[u]);
    for(int v : adj[u]){
        init_dfs(v);
    }

    tout[u] = timerDFS;
}

int count(int i, int l, int r){
    return upper_bound(all(pos[i]), r) - lower_bound(all(pos[i]), l);
}

void testcase(){
    scanf("%d%d%d", &N, &R, &Q);
    for(int i = 1; i <= N; ++i){
        if(i > 1){
            int p;
            scanf("%d", &p);
            adj[p].push_back(i);
        }

        scanf("%d", &H[i]);
        inRegion[H[i]].push_back(i);
    }

    for(int i = 1; i <= R; ++i){
        if(sz(inRegion[i]) > B){
            heavy[i] = true;
            sum[1] = 0;
            save[i].resize(N + 1);
            target = i;
            dfs(1, save[i]);
        } else{
            heavy[i] = false;
        }
    }

    init_dfs(1);

    for(int i = 1; i <= Q; ++i){
        int r1, r2;
        scanf("%d%d", &r1, &r2);
        if(heavy[r1]){
            cout << save[r1][r2] << endl;
        } else{
            ll ans = 0;
            for(int u : inRegion[r1]){
                ans += count(r2, tin[u], tout[u]);
            }

            if(r1 == r2){ //2x times
                ans -= sz(inRegion[r1]);
            }

            cout << ans << endl;
        }
    }
}

int main(){
    int T = 1;
    // cin >> T;
    while(T--){
        testcase();
    }

    return 0;
}

Compilation message (stderr)

regions.cpp: In function 'void testcase()':
regions.cpp:83:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |     scanf("%d%d%d", &N, &R, &Q);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~
regions.cpp:87:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |             scanf("%d", &p);
      |             ~~~~~^~~~~~~~~~
regions.cpp:91:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |         scanf("%d", &H[i]);
      |         ~~~~~^~~~~~~~~~~~~
regions.cpp:111:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  111 |         scanf("%d%d", &r1, &r2);
      |         ~~~~~^~~~~~~~~~~~~~~~~~

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