Submission #516798

#	Time	Username	Problem	Language	Result	Execution time	Memory
516798		Be_dos	Biochips (IZhO12_biochips)	C++17	100 / 100	672 ms	390780 KiB

biochips

#include <iostream>
#include <cmath>
#include <cctype>
#include <vector>
#include <algorithm>
#include <set>
#include <map>
#include <deque>
#include <stack>
#include <unordered_set>
#include <sstream>
#include <cstring>
#include <iomanip>
#include <queue>
#include <unordered_map>
#include <random>
#include <cfloat>
#include <chrono>
#include <bitset>
#include <complex>
#include <immintrin.h>
#include <cassert>

void dfs2(int32_t v, std::vector<int32_t>* tree, int32_t* subtree_sizes) {
    subtree_sizes[v] = 1;
    for(int32_t i = 0; i < tree[v].size(); i++) {
        dfs2(tree[v][i], tree, subtree_sizes);
        subtree_sizes[v] += subtree_sizes[tree[v][i]];
    }
}

int32_t m;
void dfs(int32_t v, std::vector<int32_t>* tree, int32_t** dp, int32_t* arr, int32_t* subtree_sizes) {
    if(tree[v].size() == 0) {
        dp[v] = new int32_t[m + 1];
        dp[v][0] = 0;
        dp[v][1] = arr[v];
        for(int32_t i = 2; i <= m; i++)
            dp[v][i] = -1'000'000'000;
        return;
    }

    int32_t best_ind = 0;
    for(int32_t i = 0; i < tree[v].size(); i++)
        if(subtree_sizes[tree[v][i]] > subtree_sizes[tree[v][best_ind]])
            best_ind = i;
    std::swap(tree[v][best_ind], tree[v][0]);

    for(int32_t i = 0; i < tree[v].size(); i++)
        dfs(tree[v][i], tree, dp, arr, subtree_sizes);

    dp[v] = dp[tree[v][0]];
    int32_t* tmp = new int32_t[m + 1];
    for(int32_t i = 1; i < tree[v].size(); i++) {
        for(int32_t j = 0; j <= m; j++) {
            tmp[j] = -1'000'000'000;
            for(int32_t k = 0; k <= std::min(j, subtree_sizes[tree[v][i]]); k++)
                tmp[j] = std::max(tmp[j], dp[v][j - k] + dp[tree[v][i]][k]);
        }
        int32_t* tmp2 = dp[v];
        dp[v] = tmp;
        tmp = tmp2;
    }
    dp[v][1] = std::max(dp[v][1], arr[v]);
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);

    int32_t n;
    std::cin >> n >> m;

    int32_t* arr = new int32_t[n];
    std::vector<int32_t>* tree = new std::vector<int32_t>[n];
    int32_t root = -1;
    for(int32_t i = 0; i < n; i++) {
        int32_t parent;
        std::cin >> parent >> arr[i];
        parent--;

        if(parent == -1)
            root = i;
        else
            tree[parent].push_back(i);
    }

    int32_t* subtree_sizes = new int32_t[n];
    dfs2(root, tree, subtree_sizes);

    int32_t** dp = new int32_t*[n];
    dfs(root, tree, dp, arr, subtree_sizes);

    std::cout << dp[root][m];
    return 0;
}
         

Compilation message (stderr)

biochips.cpp: In function 'void dfs2(int32_t, std::vector<int>*, int32_t*)':
biochips.cpp:26:26: warning: comparison of integer expressions of different signedness: 'int32_t' {aka 'int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |     for(int32_t i = 0; i < tree[v].size(); i++) {
      |                        ~~^~~~~~~~~~~~~~~~
biochips.cpp: In function 'void dfs(int32_t, std::vector<int>*, int32_t**, int32_t*, int32_t*)':
biochips.cpp:44:26: warning: comparison of integer expressions of different signedness: 'int32_t' {aka 'int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |     for(int32_t i = 0; i < tree[v].size(); i++)
      |                        ~~^~~~~~~~~~~~~~~~
biochips.cpp:49:26: warning: comparison of integer expressions of different signedness: 'int32_t' {aka 'int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |     for(int32_t i = 0; i < tree[v].size(); i++)
      |                        ~~^~~~~~~~~~~~~~~~
biochips.cpp:54:26: warning: comparison of integer expressions of different signedness: 'int32_t' {aka 'int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |     for(int32_t i = 1; i < tree[v].size(); i++) {
      |                        ~~^~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100