Submission #102305

#	Time	Username	Problem	Language	Result	Execution time	Memory
102305		MoNsTeR_CuBe	Ball Machine (BOI13_ballmachine)	C++17	25 / 100	1083 ms	19704 KiB

ballmachine

#include <bits/stdc++.h>
using namespace std;

#define int long long

vector< vector<int> > Graph;

vector<int> minLeft;
vector<int> minRight;

const int INF = 1e15;

void dfs(int x, int last){
    for(int a : Graph[x]){
        if(a == last) continue;
        dfs(a,x);
    }
    if(!Graph[x].size()){
        minLeft[x] = INF;
        minRight[x] = INF;
        return;
    }
    minLeft[x] = min(min(minLeft[Graph[x][0]], minRight[Graph[x][0]]), Graph[x][0]);
    minRight[x] = min(min(minRight[Graph[x][1]], minLeft[Graph[x][1]]), Graph[x][1]);
}

vector< bool > isFull;

int last;

void add(int node){
   // cout << node << endl;
    if(Graph[node].size() == 0 || (isFull[Graph[node][0]] && isFull[Graph[node][1]])){
        isFull[node] = true;
        last = node;
        return;
    }
    if(isFull[Graph[node][1]]) add(Graph[node][0]);
    else if(isFull[Graph[node][0]]) add(Graph[node][1]);
    else if(minLeft[node] < minRight[node]){
        add(Graph[node][0]);
    }else{
        add(Graph[node][1]);
    }
}

vector< int > up;

int tot ;

void rem(int node, int last){
    if(node == 0) return;
    if(last != -1){
        if(!isFull[last] && isFull[node]){
            tot++;
            isFull[last] = true;
            isFull[node] = false;
        }
    }
    rem(up[node], node);
}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, q;
    cin >> n >> q;
    Graph.resize(n+1);
    int root;
    up.resize(n+1);
    for(int i = 0; i < n; i++){
        int a;
        cin >> a;
        Graph[a].push_back(i+1);
        up[i+1] = a;
        if(a == 0) root = i+1;
    }

    minRight.resize(n+1);
    minLeft.resize(n+1);

    dfs(root,-1);

    isFull.resize(n+1);

    while(q--){
        int a;
        cin >> a;
        int b;
        cin >> b;
        if(a == 1){
            for(int i = 0; i < b; i++){
                add(root);
            }
            cout << last << endl;
        }else{
            isFull[b] = false;
            tot = 0;
            rem(b,-1);
            cout << tot << endl;
        }
    }
}

Compilation message (stderr)

ballmachine.cpp: In function 'int main()':
ballmachine.cpp:93:20: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
                 add(root);
                 ~~~^~~~~~

• Subtask 1: 25 / 25
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40
• Subtask 4: 0 / 5