답안 #960505

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
960505 2024-04-10T14:38:04 Z cpptowin Janjetina (COCI21_janjetina) C++17
0 / 110
12 ms 29156 KB
#include<bits/stdc++.h>
#define fo(i,d,c) for(int i=d;i<=c;i++)
#define fod(i,c,d) for(int i=c;i>=d;i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout<<"\n";
#define int long long
#define inf (int)1e18
#define pii pair<int,int>
#define vii vector<pii>
#define lb(x) x&-x
#define bit(i,j) ((i>>j)&1)
#define offbit(i,j) (i^(1<<j))
#define onbit(i,j) (i|(1<<j))
#define vi vector<int>
template <typename T1, typename T2> bool minimize(T1 &a, T2 b){if (a > b) {a = b; return true;} return false;}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b){if (a < b) {a = b; return true;} return false;}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
struct BIT
{
    int t[maxn];
    void up(int x,int val)
    {
        x++;
        for( ; x < maxn ; x += lb(x)) t[x] += val;
    }
    int get(int x)
    {
        x++;
        int ans = 0;
        for( ; x ; x -= lb(x)) ans += t[x];
        return ans;
    }
}t;
int n,k;
vii ke[maxn];
int ans;
// centroid decomposition
bool is_remove[maxn];
int tot = 0;
int sz[maxn];
int dfs_size(int u,int parent = -1)
{
    sz[u] = 1;
    for(auto [v,w] : ke[u])
    {
        if(v == parent or is_remove[v]) continue;
        sz[u] += dfs_size(v,u);
    }
    return sz[u];
}
int dfs_centroid(int u,int tree_size,int parent = 0)
{
    for(auto [v,w] : ke[u])
    {
        if(v == parent or is_remove[v]) continue;
        if(2 * sz[v] > tree_size) return dfs_centroid(v,tree_size,u);
    }
    return u;
}
void dfs_dist(int u,int par,int update,int dist,int maxx)
{
    for(auto [v,w] : ke[u])
    {
        if(v == par or is_remove[v]) continue;
        dfs_dist(v,u,update,dist + 1,max(maxx,w));
    }
    if(update == 0)
    {
        if(maxx >= k) ans += t.get(maxx - k),tot ++;
    }
    else t.up(dist,update);
}
void build_centroid(int u)
{
    u = dfs_centroid(u,dfs_size(u));
    is_remove[u] = 1;
    // do sth
    for(auto [v,w] : ke[u])
    {
        if(is_remove[v]) continue;
        dfs_dist(v,u,0,1,w);
        dfs_dist(v,u,1,1,w);
    }
    for(auto [v,w] : ke[u])
    {
        if(is_remove[v]) continue;
        dfs_dist(v,u,-1,1,w);
    }
    fod(i,ke[u].size() - 1,0)
    {
        auto [v,w] = ke[u][i];
        if(is_remove[v]) continue;
        dfs_dist(v,u,0,1,w);
        dfs_dist(v,u,1,1,w);
    }
    // cout << u << ' ' << ans << ' ' << tot;en;
    for(auto [v,w] : ke[u])
    {
        if(is_remove[v]) continue;
        build_centroid(v);
    }
}
main()
{
    #define name "TASK"
    if(fopen(name".inp","r"))
    {
       freopen(name".inp","r",stdin);
       freopen(name".out","w",stdout);
    }
    ios_base::sync_with_stdio(false);cin.tie(NULL);
    cin >> n >> k;
    fo(i,1,n - 1)
    {
        int u,v,w;
        cin >> u >> v >> w;
        ke[u].pb(v,w);
        ke[v].pb(u,w);
    }
    build_centroid(1);
    // cout << ans;en;
    cout << ans * 2 + tot / 2;
}

Compilation message

Main.cpp:109:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  109 | main()
      | ^~~~
Main.cpp: In function 'int main()':
Main.cpp:114:15: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  114 |        freopen(name".inp","r",stdin);
      |        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:115:15: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  115 |        freopen(name".out","w",stdout);
      |        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 26972 KB Output is correct
2 Incorrect 7 ms 29020 KB Output isn't correct
3 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 26972 KB Output is correct
2 Incorrect 12 ms 29156 KB Output isn't correct
3 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 26972 KB Output is correct
2 Incorrect 7 ms 29020 KB Output isn't correct
3 Halted 0 ms 0 KB -