Submission #472917

#TimeUsernameProblemLanguageResultExecution timeMemory
472917MohamedFaresNebiliRegions (IOI09_regions)C++14
80 / 100
8070 ms36604 KiB
#include <bits/stdc++.h>

        using namespace std;

        using ll  = long long;
        using ld  = long double;
        using ii  = pair<int, int>;

        using vl  = vector<long long>;

        #define mp make_pair
        #define pb push_back
        #define pp pop_back
        #define ff first
        #define ss second
        #define lb lower_bound
        #define ub upper_bound
        #define all(x) (x).begin() , (x).end()

        const int N = 2*100005;
        const long long MOD = 1e9+7;
        const long double EPS = 0.000000001;
        const double PI = 3.14159265358979323846;
        const int nx[4]={1, -1, 0, 0}, ny[4]={0, 0, 1, -1};

        long long gcd(int a, int b) { return (b==0?a:gcd(b, a%b)); }
        long long lcm(int a, int b) { return  a*(b/gcd(a, b)); }
        long long fact(int a) { return (a==1?1:a*fact(a-1)); }

        int n, r, q, timer=0, arr[200005], tin[200005], out[200005];
        vector<int>adj[200005], se[25005]; vector<int>home[25005]; map<ii, int>dp;
        void dfs(int v, int p) {
            tin[v]=++timer; se[arr[v]].pb(timer);
            for(auto u:adj[v]) {
                if(u==p) continue;
                dfs(u, v);
            }
            out[v]=++timer;
        }

        int32_t main()
        {
            ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
            cin>>n>>r>>q; cin>>arr[1]; home[arr[1]].pb(1);
            for(int l=2;l<=n;l++) {
                int a, h; cin>>a>>h; home[h].pb(l);
                adj[a].pb(l); adj[l].pb(a); arr[l]=h;
            }
            dfs(1, 1);
            while(q--) {
                int a, b; cin>>a>>b; int res=0;
                if(dp.find({a, b})!=dp.end()) { cout<<dp[{a, b}]<<"\n"<<flush; continue; }
                for(auto u:home[a]) {
                    int l=tin[u], r=out[u];
                    int add=lb(all(se[b]), r)-lb(all(se[b]), l);
                    res+=add;
                }
                dp[{a, b}]=res; cout<<res<<"\n"<<flush;
            }
            return 0;
        }
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