Submission #986406

#	Time	Username	Problem	Language	Result	Execution time	Memory
986406		Neco_arc	Cat in a tree (BOI17_catinatree)	C++17	100 / 100	373 ms	263880 KiB

catinatree

#include <bits/stdc++.h>
//#include <bits/debug.hpp>

#define ll long long
#define all(x) x.begin(), x.end()
#define Neco "Maximum Weight Subset"
#define resp(x) sort(all(x)), x.resize(unique(all(x)) - x.begin())
#define getbit(x,i) ((x >> i)&1)
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define cntbit(x) __builtin_popcountll(x)
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)
#define maxn (int) 2e5 + 7

using namespace std;

const ll mod = 1e9 + 7; //972663749
const ll base = 911382323;

int n, k;
int a[maxn];
vector<int> edges[maxn];
deque<int> dp[maxn];

void dfs(int u, int par) {
    dp[u] = {1};

    for(int v : edges[u]) if(v != par) {
        dfs(v, u);

        if(dp[u].size() < dp[v].size()) swap(dp[u], dp[v]);
        fi(i, 0, dp[v].size() - 1) {
            int x = max(k - i, i);
            int w1 = dp[v][i] + (x < dp[u].size() ? dp[u][x] : 0);
            int w2 = dp[u][i] + (x < dp[v].size() ? dp[v][x] : 0);

            dp[u][i] = max({dp[u][i], w1, w2});
        }

        fid(i, dp[v].size() - 1, 0) {
            if(i + 1 < dp[u].size()) dp[u][i] = max(dp[u][i], dp[u][i + 1]);
        }
    }

    dp[u].push_front(dp[u].front());
}

void solve()
{

    cin >> n >> k;
    fi(i, 2, n) {
        int x; cin >> x, ++x;
        edges[x].push_back(i);
    }

    dfs(1, 0);
    cout << dp[1][0];

}


int main()
{

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if(fopen(Neco".inp", "r")) {
        freopen(Neco".inp", "r", stdin);
        freopen(Neco".out", "w", stdout);
    }


    int nTest = 1;
//    cin >> nTest;


    while(nTest--)
    {
        solve();
    }


    return 0;
}

Compilation message (stderr)

catinatree.cpp: In function 'void dfs(int, int)':
catinatree.cpp:12:38: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 | #define fi(i, a, b) for(int i = a; i <= b; i++)
......
   33 |         fi(i, 0, dp[v].size() - 1) {
      |            ~~~~~~~~~~~~~~~~~~~~~~     
catinatree.cpp:33:9: note: in expansion of macro 'fi'
   33 |         fi(i, 0, dp[v].size() - 1) {
      |         ^~
catinatree.cpp:35:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |             int w1 = dp[v][i] + (x < dp[u].size() ? dp[u][x] : 0);
      |                                  ~~^~~~~~~~~~~~~~
catinatree.cpp:36:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |             int w2 = dp[u][i] + (x < dp[v].size() ? dp[v][x] : 0);
      |                                  ~~^~~~~~~~~~~~~~
catinatree.cpp:42:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |             if(i + 1 < dp[u].size()) dp[u][i] = max(dp[u][i], dp[u][i + 1]);
      |                ~~~~~~^~~~~~~~~~~~~~
catinatree.cpp: In function 'int main()':
catinatree.cpp:72:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |         freopen(Neco".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
catinatree.cpp:73:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |         freopen(Neco".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 40 / 40
• Subtask 3: 49 / 49