Submission #790103

#	Time	Username	Problem	Language	Result	Execution time	Memory
790103		TB_	Cat in a tree (BOI17_catinatree)	C++17	100 / 100	73 ms	24604 KiB

catinatree

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

// #undef _GLIBCXX_DEBUG                // disable run-time bound checking, etc
// #pragma GCC optimize("Ofast,inline") // Ofast = O3,fast-math,allow-store-data-races,no-protect-parens
// #pragma GCC optimize ("unroll-loops")

// #pragma GCC target("bmi,bmi2,lzcnt,popcnt")                      // bit manipulation
// #pragma GCC target("movbe")                                      // byte swap
// #pragma GCC target("aes,pclmul,rdrnd")                           // encryption
// #pragma GCC target("avx,avx2,f16c,fma,sse3,ssse3,sse4.1,sse4.2") // SIMD

// #include <bits/extc++.h>
// using namespace __gnu_pbds;
// template<class T>using ordered_set = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
// template<class T>using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define ll long long
#define INF (ll)1e9+7
#define fo(i, n) for(int i=0;i<n;i++)
#define deb(x) cout << #x << " = " << x << endl;
#define deb2(x, y) cout << #x << " = " << x << ", " << #y << " = " << y << endl
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define LSOne(S) ((S) & (-S))
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
inline int readint(){ int v = 0; char c; while((c = getchar()) != EOF && c != ' ' && c != '\n'){ v *= 10; v += c - '0'; } return v; }
inline int readintsigned() { int v = 0; int sign = 1; char c = getchar(); if (c == '-') { sign = -1; } else { v += c - '0'; } while ((c = getchar()) != EOF && c != ' ' && c != '\n') { v *= 10; v += c - '0'; } return v * sign; }
inline string readstring() { string s; char c; while ((c = getchar()) != EOF && c != '\n' && c != ' ') { s.push_back(c); } return s; }
template <class result_t=std::chrono::milliseconds,class clock_t=std::chrono::steady_clock,class duration_t = std::chrono::milliseconds>
auto since(std::chrono::time_point<clock_t, duration_t> const& start){return std::chrono::duration_cast<result_t>(clock_t::now() - start);}
typedef pair<int, int> pii;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpii;
typedef vector<pl> vpl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef vector<vpii> vvpii;
typedef vector<vpl> vvpl;

vvl adj(2e5+1);

int d;

pl solve(int pos, int last = -1){ // closest, sum
    vpl subTrees;
    for(auto v : adj[pos]){
        if(v == last) continue;
        subTrees.pb(solve(v, pos));
    }
    pl ans = {1e16, 0};
    sort(rall(subTrees));

    fo(i, subTrees.size()){
        if(!subTrees[i].S) continue;
        ans.S += subTrees[i].S;
        if(subTrees[i].F+ans.F>=d){
            ans.F = subTrees[i].F;
        }else ans.S--;
    }
    if(ans.F>=d){
        ans.F = 0;
        ans.S++;
    }
    ans.F++;
    return ans;
}

int main() {
    // cout << fixed << setprecision(20);
    // auto start = std::chrono::steady_clock::now(); // since(start).count()
    cin.tie(0)->sync_with_stdio(0);

    int n, to;
    cin >> n >> d;
    fo(i, n-1){
        cin >> to;
        adj[i+1].pb(to);
        adj[to].pb(i+1);
    }
    cout << solve(0).S;

    return 0;
}

Compilation message (stderr)

catinatree.cpp: In function 'pl solve(int, int)':
catinatree.cpp:20:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 | #define fo(i, n) for(int i=0;i<n;i++)
......
   59 |     fo(i, subTrees.size()){
      |        ~~~~~~~~~~~~~~~~~~      
catinatree.cpp:59:5: note: in expansion of macro 'fo'
   59 |     fo(i, subTrees.size()){
      |     ^~

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