제출 #1275250

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1275250		minhvule	Janjetina (COCI21_janjetina)	C++20	0 / 110	2 ms	576 KiB

Main

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

#define task "task"
#define fi first
#define se second
#define pb push_back
#define FOR(i, a, b) for(int i = (a), _b = (b); i <= _b; i ++)
#define FORD(i, a, b) for(int i = (a), _b = (b); i >= _b; i --)
#define bit(x, i) ((x >> i) & 1)
#define oo 1e18
#define all(v) v.begin(), v.end()

using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
// mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
// ll rand(ll l, ll r) { assert(l <= r); return uniform_int_distribution<ll>(l, r)(rd); }
const int N = 1e5 + 5;
const int mod = 1e9 + 7;
const int base = 31;
int n, k, sz[N], ans = 0, bit[N];
vector<pii> g[N];
bool del[N], mark[N];
int sus = 0;
void init(void){
    cin>>n>>k;
    FOR(i, 1, n - 1){
        int u, v, w; cin>>u>>v>>w;
        g[u].pb({v, w});
        g[v].pb({u, w});
    }
}
int dfs_sz(int u, int p){
    sz[u] = 1;
    for(auto [v, w] : g[u]) if(v != p && !del[v]){
        sz[u] += dfs_sz(v, u);
    }
    return sz[u];
}
int findCentroid(int u, int p, int child){
    for(auto [v, w] : g[u]) if(v != p && !del[v] && sz[v] > child / 2)
        return findCentroid(v, u, child);
    return u;
}
vector<pii> val;
void dfs(int u, int p, int d, int W){
    val.pb({W, d});
    for(auto [v, w] : g[u]) if(v != p && !del[v])
        dfs(v, u, d + 1, max(W, w));
}
void update(int i, int val){
    for(i; i < N; i += i&-i){
        if(mark[i] != sus){
            mark[i] = sus;
            bit[i] = 0;
        }
        bit[i] += val;
    }
}
int get(int i){
    int ans = 0;
    for(i; i > 0; i -= i&-i){
        if(mark[i] != sus){
            mark[i] = sus;
            bit[i] = 0;
        }
        ans += bit[i];
    }
    return ans;
}
void calc(int u){
    sus ^= 1;
    int child = dfs_sz(u, 0);
    int c = findCentroid(u, 0, child);
    val.clear();
    val.pb({-1e9, 0});
    for(auto [v, w] : g[c]) if(!del[v])
        dfs(v, c, 1, w);
    sort(val.begin(), val.end());
    for(auto [w, d] : val){
        if(w - d - k >= 0) ans += get(w - d - k + 1);
        update(d + 1, 1);
    }
    for(auto [v, w] : g[c]) if(!del[v]){
        val.clear();
        dfs(v, c, 1, w);
        sort(val.begin(), val.end());
        sus ^= 1;
        for(auto [w, d] : val){
            if(w - d - k > 0) ans -= get(w - d - k + 1);
            update(d + 1, 1);
        }
    }
    del[c] = 1;
    for(auto [v, w] : g[c]) if(!del[v]) calc(v);
}
void solve(){
    init();
    calc(1);
    cout<<ans * 2;
}
signed main(){
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    if(fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    int nTest = 1;
    // cin>>nTest;
    while(nTest --) solve();
    // cerr << "\nTime: " << 1.0 * clock() / CLOCKS_PER_SEC << "s\n";
    return 0;
}
/*



*/

컴파일 시 표준 에러 (stderr) 메시지

Main.cpp: In function 'int main()':
Main.cpp:107:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  107 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:108:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  108 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 35
• Subtask 3: 0 / 60