Submission #392295

#	Time	Username	Problem	Language	Result	Execution time	Memory
392295		achibasadzishvili	Regions (IOI09_regions)	C++17	80 / 100	8079 ms	56460 KiB

regions

#include<bits/stdc++.h>
#define ll int
#define f first
#define s second
#define pb push_back
using namespace std;
const int N = 200005;
ll n,r,q,sq,pown = 1;
ll timer,in[N],out[N],t[4 * N],cur,c[N],p[N],ch[N],ind[26000];
vector<ll>v[N],g[N];
int ans[700][26000],rev[700][26000];
void go(ll x){
    timer++;
    in[x] = timer;
    for(auto to : v[x]){
        go(to);
    }
    out[x] = timer;
}
void upd(ll x){
    if(!x)return;
    t[x] = t[2 * x] + t[2 * x + 1];
    upd(x / 2);
}
ll get(ll x,ll L,ll R,ll l,ll r){
    if(L > r || R < l)return 0;
    if(L >= l && R <= r)return t[x];
    ll k1 = get(2 * x , L , (L + R) / 2 , l , r);
    ll k2 = get(2 * x + 1 , (L + R) / 2 + 1 , R , l , r);
    return k1 + k2;
}
void solve(ll x,ll y){
    cur += (c[x] == y);
    ch[x] = (c[x] == y);
    for(auto to : v[x]){
        solve(to , y);
        ch[x] += ch[to];
    }
    if(c[x] != y){
        rev[ind[y]][c[x]] += ch[x];
        ans[ind[y]][c[x]] += cur;
    }
    cur -= (c[x] == y);
}
int main(){
    cin >> n >> r >> q;
    sq = n / 700;
    vector<int>big;
    while(pown <= n)
        pown *= 2;
    cin >> c[1];
    g[c[1]].pb(1);
    for(int i=2; i<=n; i++){
        cin >> p[i] >> c[i];
        g[c[i]].pb(i);
        v[p[i]].pb(i);
    }
    
    go(1);
    for(int i=1; i<=r; i++){
        if(g[i].size() >= sq){
            big.pb(i);
            ind[i] = big.size();
        }
    }
    
    for(auto a : big){
        for(int i=1; i<=r; i++){
            ans[ind[a]][i] = 0;
            rev[ind[a]][i] = 0;
        }
        solve(1 , a);
    }
    ll x,y;
    while(q--){
        cin >> x >> y;
        if(g[x].size() >= sq){
            cout << ans[ind[x]][y] << endl;
            continue;
        }
        if(g[y].size() >= sq){
            cout << rev[ind[y]][x] << endl;
            continue;
        }
        for(auto a : g[y]){
            t[pown + in[a] - 1]++;
            upd((pown + in[a] - 1) / 2);
        }
        ll ret = 0;
        for(auto a : g[x]){
            ret += get(1 , 1 , pown , in[a] , out[a]);
        }
        for(auto a : g[y]){
            t[pown + in[a] - 1]--;
            upd((pown + in[a] - 1) / 2);
        }
        cout << ret << endl;
    }
    
    
    return 0;
}

Compilation message (stderr)

regions.cpp: In function 'int main()':
regions.cpp:61:24: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   61 |         if(g[i].size() >= sq){
      |            ~~~~~~~~~~~~^~~~~
regions.cpp:77:24: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   77 |         if(g[x].size() >= sq){
      |            ~~~~~~~~~~~~^~~~~
regions.cpp:81:24: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   81 |         if(g[y].size() >= sq){
      |            ~~~~~~~~~~~~^~~~~

• Subtask 1: 15 / 15
• Subtask 2: 65 / 85