Submission #1045089

#	Time	Username	Problem	Language	Result	Execution time	Memory
1045089		Beerus13	Janjetina (COCI21_janjetina)	C++14	110 / 110	248 ms	15816 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define FOR(i, a, b)  for(int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, b, a) for(int i = (b), _a = (a); i >= _a; --i)
#define REP(i, a, b)  for(int i = (a), _b = (b); i < _b;  ++i)
#define REPD(i, b, a) for(int i = (b), _a = (a); i > _a;  --i)
#define MASK(i) (1LL << (i))
#define BIT(mask, i) (((mask) >> (i)) & 1)
#define __builtin_popcount __builtin_popcountll
#define all(val) val.begin(), val.end()
#define ll long long
#define ull unsigned long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define sz(v) (int)v.size()
#define fi first
#define se second

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll Rand(ll l, ll r) {return l + rng() % (r - l + 1);}

template<class X, class Y>
    bool minimize(X &x, const Y &y) {
        if (x > y) {
            x = y;
            return true;
        } else return false;
    }
template<class X, class Y>
    bool maximize(X &x, const Y &y) {
        if (x < y) {
            x = y;
            return true;
        } else return false;
    }
template<class T>
    T Abs(const T &x) {
        return (x < 0 ? -x : x);    
    }

const int mod = 1e9 + 7;
const int N = 1e5 + 5;

int bit[N];

void update(int i, int val) {
    for(; i < N; i += i & -i) bit[i] += val; 
}

int get(int i) {
    int res(0);
    for(; i; i -= i & -i) res += bit[i];
    return res;
}

int n, k;
int sz[N], cnt[N];
bool del[N];
vector<pii> g[N], res;
ll ans;

int dfs_size(int u, int p = 0) {
    sz[u] = 1;
    for(auto [v, w] : g[u]) if(v != p && !del[v]) sz[u] += dfs_size(v, u);
    return sz[u];
}

int find_centroid(int u, int p, int num) {
    for(auto [v, w] : g[u]) if(v != p && !del[v] && sz[v] > num / 2)
        return find_centroid(v, u, num);
    return u;
}

void dfs(int u, int p, int dep, int val) {
    res.emplace_back(val, dep);
    for(auto [v, w] : g[u]) if(v != p && !del[v])
        dfs(v, u, dep + 1, max(val, w));
}

ll compute(vector<pii> &res) {
    sort(all(res));
    ll ans(0);
    for(auto [w, len] : res) {
        if(w >= len) ans += get(w - len);
        update(k + len, 1);
    }
    for(auto [w, len] : res) {
        update(k + len, -1);
    }
    return ans;
}

void decomposition(int u) {
    u = find_centroid(u, 0, dfs_size(u));
    del[u] = 1;
    res.clear();
    dfs(u, 0, 0, 0);
    ans += compute(res);
    for(auto [v, w] : g[u]) if(!del[v]) {
        res.clear();
        dfs(v, u, 1, w);
        ans -= compute(res);
    }
    for(auto [v, w] : g[u]) if(!del[v])
        decomposition(v);
}

void process() {
    cin >> n >> k;
    REP(i, 1, n) {
        int u, v, w; cin >> u >> v >> w;
        g[u].emplace_back(v, w);
        g[v].emplace_back(u, w);
    }
    decomposition(1);
    cout << ans * 2 << '\n';
}

signed main() {
    if(fopen("COCI21_janjetina.inp","r")) {
        freopen("COCI21_janjetina.inp","r",stdin);
        freopen("COCI21_janjetina.out","w",stdout);
    }
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    // clock_t start = clock();

    int ntests = 1;
    // cin >> ntests;
    while(ntests--) process();

    // cerr << "Time elapsed: " << clock() - start << " ms!\n";
    return 0;
}
// https://oj.uz/problem/view/COCI21_janjetina

Compilation message (stderr)

Main.cpp: In function 'int dfs_size(int, int)':
Main.cpp:64:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   64 |     for(auto [v, w] : g[u]) if(v != p && !del[v]) sz[u] += dfs_size(v, u);
      |              ^
Main.cpp: In function 'int find_centroid(int, int, int)':
Main.cpp:69:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   69 |     for(auto [v, w] : g[u]) if(v != p && !del[v] && sz[v] > num / 2)
      |              ^
Main.cpp: In function 'void dfs(int, int, int, int)':
Main.cpp:76:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   76 |     for(auto [v, w] : g[u]) if(v != p && !del[v])
      |              ^
Main.cpp: In function 'long long int compute(std::vector<std::pair<int, int> >&)':
Main.cpp:83:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   83 |     for(auto [w, len] : res) {
      |              ^
Main.cpp:87:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   87 |     for(auto [w, len] : res) {
      |              ^
Main.cpp: In function 'void decomposition(int)':
Main.cpp:99:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   99 |     for(auto [v, w] : g[u]) if(!del[v]) {
      |              ^
Main.cpp:104:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  104 |     for(auto [v, w] : g[u]) if(!del[v])
      |              ^
Main.cpp: In function 'int main()':
Main.cpp:121:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  121 |         freopen("COCI21_janjetina.inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:122:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  122 |         freopen("COCI21_janjetina.out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 35 / 35
• Subtask 3: 60 / 60