Submission #1020411

#	Time	Username	Problem	Language	Result	Execution time	Memory
1020411		anHiep	Untitled (POI11_rot)	C++17	0 / 100	37 ms	65536 KiB

Main

#include<bits/stdc++.h>

using namespace std;

#define fi first 
#define se second
#define pb push_back
#define ll long long
#define ii pair<int, int>
#define vi vector<int> 
#define vll vector<ll>
#define vii vector<ii>
#define cd complex<double>
const ll mod = 1e9 + 7;
const ll INF = 1e18L + 5;
const double PI = acos(-1);
const int block = 320;
const int N = 1e7;
int tc, tt = 1;

int n, u, v;
int tdfs = 0, cnt = 0;
int a[N + 5], sz[N + 5];
vi g[N + 5];
set<int> s[N + 5];
ll dp[N + 5];
void build_tree(int u) {
    for(int i=1; i<=2; i++) {
        int x;
        cin>>x;
        if(x == 0) {
            tdfs++;
            g[u].pb(tdfs);
            build_tree(tdfs);
        }
        else {
            tdfs++;
            g[u].pb(tdfs);
            a[tdfs] = x;
            cnt++;
        }
        if(cnt == n) return;
    }
}
struct fenwick_tree {
    int bit[N + 5];
    void update(int pos, int v) {
        while(pos <= n) {
            bit[pos] += v;
            pos += (pos & (-pos));
        }
    }
    int get(int pos) {
        int ans = 0;
        while(pos) {
            ans += bit[pos];
            pos -= (pos & (-pos));
        }
        return ans;
    }
} ft;
void dfs_sz(int u, int par) {
    sz[u] = 1;
    for(auto v: g[u])
        if(v != par) {
            dfs_sz(v, u);
            sz[u] += sz[v];
        } 
} 
void dfs(int u, int par) {
    int bc = 0;
    for(auto v: g[u])
        if(v != par && sz[v] > sz[bc]) bc = v;
    for(auto v: g[u])
        if(v != par && v != bc) {
            dfs(v, u);
            dp[u] += dp[v];
            for(auto x: s[v])
                ft.update(x, -1);
        }
    if(bc) {
        dfs(bc, u);
        dp[u] += dp[bc];
        swap(s[bc], s[u]);
    }
    if(a[u] != -1) {
        ft.update(a[u], 1);
        s[u].insert(a[u]);
    }
    if((int)g[u].size() == 0) return;
    ll c1 = 0, c2 = 0;
    for(auto v: g[u])
        if(v != par && v != bc) {
            for(auto x: s[v]) {
                c1 += ft.get(x - 1);
                c2 += ft.get(n) - ft.get(x);
                s[u].insert(x);
            }
        }
    for(auto v: g[u])
        if(v != par && v != bc) 
            for(auto x: s[v]) 
                ft.update(x, 1);
    dp[u] += min(c1, c2);
}
void solve() {
    memset(a, -1, sizeof(a));
    cin>>n;
    build_tree(0);
    n = tdfs;
    dfs_sz(1, -1);
    dfs(1, -1);
    cout<<dp[1];
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    // freopen(".INP", "r", stdin);
    // freopen(".OUT", "w", stdout);
    for(tc=1; tc<=tt; tc++) solve();
    return 0;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 9
• Subtask 3: 0 / 9
• Subtask 4: 0 / 9
• Subtask 5: 0 / 9
• Subtask 6: 0 / 9
• Subtask 7: 0 / 9
• Subtask 8: 0 / 9
• Subtask 9: 0 / 9
• Subtask 10: 0 / 9
• Subtask 11: 0 / 10