oj.uz

Submission #242123

# Submission time Handle Problem Language Result Execution time Memory
242123 2020-06-26T22:19:51 Z pauloamed Ball Machine (BOI13_ballmachine) C++14
100 / 100
 211 ms 20728 KB 
#include<bits/stdc++.h>
using namespace std;

#define MAXV 110000
#define MAXLOG 17

vector<int> v[MAXV]; // lista de adj

int st[MAXV][MAXLOG]; // sparse table (x,i) guardando ancestral de ordem 2^i de x
int lvl[MAXV]; // lvl=profundidade de cada no
int bit[MAXV];
int pos_id[MAXV];
int id_pos[MAXV];
int pos_cont = 0;
bool active[MAXV];

int query( int index ){
    if(index < 0 || index > MAXV) return 0;
    int ans(0); // acumulado
    index++; // bit eh 1-indexada, tem q ser feito se index for 0-indexado
    while(index > 0){ // enquanto posso ir pra esquerda
        ans += bit[index]; // atualizando o acumulado
        index -= index & (-index); // indo pro irmao a esquerda
    }
    return ans; // ret acumulado
}


void update(int index, int val){
    if(index < 0 || index > MAXV) return;
    index++; // bit eh 1-indexada
    while(index <= MAXV){ // enquanto eu puder subir na BIT
        bit[index] += val; // atualizando valores dos ancestrais
        index += index & (-index); // subindo pro pai
    }
}


void init_dfs(int x, int pai, bool jafoi[]){
    jafoi[x] = true; // marcando vertice como visitado
    st[x][0] = pai; // o ancestral de ordem 2^0 (1) de x eh o pai dele
    // se tiver pai valido (!= raiz), a prof aumenta em 1
    if(pai != -1) lvl[x] = lvl[pai]+1;
    for(int i = 0; i < v[x].size(); ++i) // visitar todos adjacentes
        if(!jafoi[v[x][i]]) init_dfs(v[x][i], x, jafoi); // passo recursivo

    pos_id[pos_cont] = x;
    id_pos[x] = pos_cont;
    pos_cont++;
}


void init(int root, int n){ // funcao init, raiz e #nos
    bool *jafoi = new bool[n]; // visitados
    init_dfs(root, root, jafoi); // calcular os ancestrais imediatos
    delete[] jafoi;
    for(int x = 1; x < MAXLOG; ++x){
        // 2^0 ja foi calculado, calculo pro resto
        for(int i = 0; i < MAXV; ++i){ // pra cada vertice
            if(i == root){
                st[i][x] = root;
            }else{
                // olho o ancestral 2^(i-1) do meu 2^(i-1), achando entao o meu 2^i
                st[i][x] = st[st[i][x-1]][x-1];
            }
        }
    }
}



int smallest[MAXV];
bool cmp(const int a, const int b){
    return smallest[a] < smallest[b];
}
void find_smallest(int x){
    smallest[x] = x;
    for(int i = 0; i < v[x].size(); ++i){
        find_smallest(v[x][i]);
        smallest[x] = min(smallest[x], smallest[v[x][i]]);
    }
}


int first_zero(){
    int ans = 0;
    if(bit[1] == 0) return 0;
    for(int i = MAXLOG-1; i >= 0; --i){
        int maybe_ans = (ans | (1<<i)); // novo indice se o bit for ativo
        if(maybe_ans >= MAXV) continue; // caso ultrapasse o limite no calc do indice
        // printf("%d %d %d\n", maybe_ans, bit[maybe_ans], (1<<i));
        if(bit[maybe_ans] == (1 << i)) ans = maybe_ans;
    }
    // cout << ans << endl;
    return ans;
}


int add(int k){
    // procura na bit o primeiro zero
    // bota o primeiro zero la
    // retorn a posicao
    int ans;
    while(k--){
        ans = first_zero();
        update(ans, 1);
        active[ans] = true;
    }
    return ans;
}

int remove(int x){
    // acha o ultimo pai q eh 1
    // se nao tem, retorna X
    // se tem, tira ele da bit e bota em X
    int curr = x;
    // cerr << "::" << x << endl;
    for(int i = MAXLOG-1; i >= 0; --i){
        int maybe_next = st[curr][i];
        int pos_maybe_next = id_pos[maybe_next];
        if(active[pos_maybe_next]){
            curr = maybe_next;
        }
    }

    // cerr << "::" << curr << " " << x << endl;
    // cerr << "::" << id_pos[curr] << " " << id_pos[x] << endl;

    update(id_pos[curr], -1);
    active[id_pos[curr]] = false;

    return lvl[x] - lvl[curr];
}


int main(){
    // add: achar a primeira posicao que é zero
    // remove: subir com binary lifting ate o pai ta ocupado
    int n, q; scanf("%d %d", &n, &q);
    int root;
    for(int i = 0; i < n; ++i){
        int x; scanf("%d", &x);
        if(x == 0) root = i;
        else v[x-1].push_back(i);
    }

    find_smallest(root);
    for(int i = 0; i < n; ++i){
        sort(v[i].begin(), v[i].end(), cmp);
    }

    init(root, n);

    // for(int i = 0; i < n; ++i){
    //     printf("%d ", id_pos[i]);
    // }printf("\n");

    while(q--){
        // for(int i = 0; i < n; ++i){
        //     printf("(%d) %d: %d\n", i, pos_id[i] + 1, query(i) - query(i - 1));
        // }
        // printf("\n");
        int x; scanf("%d", &x);
        if(x == 1){
            int k; scanf("%d", &k);
            printf("%d\n", pos_id[add(k)] + 1);
        }else{
            int y; scanf("%d", &y);
            printf("%d\n", remove(y - 1));
        }
    }
}

Compilation message

ballmachine.cpp: In function 'void init_dfs(int, int, bool*)':
ballmachine.cpp:44:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < v[x].size(); ++i) // visitar todos adjacentes
                    ~~^~~~~~~~~~~~~
ballmachine.cpp: In function 'void find_smallest(int)':
ballmachine.cpp:78:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < v[x].size(); ++i){
                    ~~^~~~~~~~~~~~~
ballmachine.cpp: In function 'int main()':
ballmachine.cpp:139:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     int n, q; scanf("%d %d", &n, &q);
               ~~~~~^~~~~~~~~~~~~~~~~
ballmachine.cpp:142:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         int x; scanf("%d", &x);
                ~~~~~^~~~~~~~~~
ballmachine.cpp:163:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         int x; scanf("%d", &x);
                ~~~~~^~~~~~~~~~
ballmachine.cpp:165:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             int k; scanf("%d", &k);
                    ~~~~~^~~~~~~~~~
ballmachine.cpp:168:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             int y; scanf("%d", &y);
                    ~~~~~^~~~~~~~~~
ballmachine.cpp: In function 'int add(int)':
ballmachine.cpp:109:12: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return ans;
            ^~~
ballmachine.cpp: In function 'int main()':
ballmachine.cpp:152:9: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
     init(root, n);
     ~~~~^~~~~~~~~

Subtask #1
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 10240 KB Output is correct
2 Correct 118 ms 12792 KB Output is correct
3 Correct 87 ms 12792 KB Output is correct
4 Correct 17 ms 10240 KB Output is correct
5 Correct 16 ms 10368 KB Output is correct
6 Correct 17 ms 10240 KB Output is correct
7 Correct 19 ms 10368 KB Output is correct
8 Correct 18 ms 10240 KB Output is correct
9 Correct 23 ms 10496 KB Output is correct
10 Correct 35 ms 10880 KB Output is correct
11 Correct 129 ms 12792 KB Output is correct
12 Correct 87 ms 12792 KB Output is correct
13 Correct 114 ms 12536 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 62 ms 12280 KB Output is correct
2 Correct 198 ms 16760 KB Output is correct
3 Correct 102 ms 13556 KB Output is correct
4 Correct 92 ms 12408 KB Output is correct
5 Correct 95 ms 12280 KB Output is correct
6 Correct 90 ms 12280 KB Output is correct
7 Correct 85 ms 11768 KB Output is correct
8 Correct 64 ms 12280 KB Output is correct
9 Correct 188 ms 17144 KB Output is correct
10 Correct 192 ms 16760 KB Output is correct
11 Correct 173 ms 16504 KB Output is correct
12 Correct 154 ms 15352 KB Output is correct
13 Correct 118 ms 18984 KB Output is correct
14 Correct 96 ms 13424 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 91 ms 13944 KB Output is correct
2 Correct 184 ms 15864 KB Output is correct
3 Correct 125 ms 18424 KB Output is correct
4 Correct 120 ms 15864 KB Output is correct
5 Correct 128 ms 15480 KB Output is correct
6 Correct 126 ms 15480 KB Output is correct
7 Correct 139 ms 14584 KB Output is correct
8 Correct 152 ms 18552 KB Output is correct
9 Correct 183 ms 17504 KB Output is correct
10 Correct 180 ms 17144 KB Output is correct
11 Correct 189 ms 17144 KB Output is correct
12 Correct 174 ms 15864 KB Output is correct
13 Correct 199 ms 20728 KB Output is correct
14 Correct 138 ms 13940 KB Output is correct

Subtask #4
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 190 ms 17400 KB Output is correct
2 Correct 211 ms 15736 KB Output is correct
3 Correct 128 ms 20216 KB Output is correct
4 Correct 200 ms 17400 KB Output is correct
5 Correct 205 ms 16892 KB Output is correct
6 Correct 149 ms 16632 KB Output is correct
7 Correct 184 ms 15736 KB Output is correct
8 Correct 124 ms 20216 KB Output is correct
9 Correct 107 ms 13684 KB Output is correct