Submission #517058

#	Time	Username	Problem	Language	Result	Execution time	Memory
517058		Yuisuyuno	Regions (IOI09_regions)	C++14	35 / 100	8098 ms	32140 KiB

regions

//Nguyen Huu Hoang Minh
#include <bits/stdc++.h>
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define reset(x) memset(x, 0,sizeof(x))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define N 200005
#define remain(x) if (x > MOD) x -= MOD
#define ii pair<int, int>
#define iiii pair< ii , ii >
#define viiii vector< iiii >
#define vi vector<int>
#define vii vector< ii >
#define bit(x, i) (((x) >> (i)) & 1)
#define Task "test"
#define int long long

using namespace std;

typedef long double ld;
const int inf = 1e10;
const int minf = -1e10;

int n, r, q;
int id[N], in[N], ou[N], cnt;
vector<int> g[N];
vector<int> reg[25005], node[25005];
int ans[450][25005], ID[25005];

void readfile()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    if (fopen(Task".inp","r"))
    {
        freopen(Task".inp","r",stdin);
        //freopen(Task".out","w",stdout);
    }
    cin >> n >> r >> q; int x; cin >> x; id[1] = x; node[x].pb(1);
    for(int i=2; i<=n; i++){
        int x, y; cin >> x >> y;
        g[x].pb(i);
        id[i] = y;
        node[y].pb(i);
    }
}

void dfs(int u){
    in[u] = ++cnt;
    reg[id[u]].pb(in[u]);
    for(auto v : g[u]){
        dfs(v);
    }
    ou[u] = ++cnt;
}

bool is_in(int inn, int oun){
    return in[oun] <= in[inn] && in[inn] < ou[oun];
}

void proc()
{
    dfs(1);
    int cnt = 0;
    for(int r1=1; r1<=r; r1++){
        if (node[r1].size()==0) continue;
        if (node[r1].size()<447) continue;
        cnt++;
        ID[r1] = cnt;
        for(auto x : node[r1]){
            for(int i=1; i<=n; i++) if (i!=x){
                if (is_in(i,x)) ans[cnt][id[i]]++;
            }
        }
    }
    while (q--){
        int u, v;
        cin >> u >> v;
        int res = 0;
        if (node[u].size()>=447){
            cout << ans[ID[u]][id[v]] << '\n';
            cout.flush();
            continue;
        }
        for(auto x : node[u]){
            int itr = lower_bound(all(reg[v]),ou[x])-reg[v].begin();
            int itl = lower_bound(all(reg[v]),in[x])-reg[v].begin();
            res += itr - itl;
        }
        cout << res << '\n';
        cout.flush();
    }
}

signed main()
{
    readfile();
    proc();
    return 0;
}

Compilation message (stderr)

regions.cpp: In function 'void readfile()':
regions.cpp:39:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |         freopen(Task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 20 / 85