Submission #725826

#	Time	Username	Problem	Language	Result	Execution time	Memory
725826		MohammadAghil	Worst Reporter 4 (JOI21_worst_reporter4)	C++17	0 / 100	6 ms	8276 KiB

worst_reporter2

#include <bits/stdc++.h>
using namespace std;
#define rep(i,l,r) for(int i = (l); i < (r); i++)
#define per(i,r,l) for(int i = (r); i >= (l); i--)
#define all(x) begin(x), end(x)
#define sz(x) (int)size(x)
#define pb push_back
#define ff first
#define ss second
typedef long long ll;
typedef pair<int, int> pp;

void dbg(){
     cerr << endl;
}
template<typename H, typename... T> void dbg(H h, T... t){
     cerr << h << ", ";
     dbg(t...);
}

void IOS(){
     cin.tie(0) -> sync_with_stdio(0);
     #ifndef ONLINE_JUDGE
          freopen("inp.txt", "r", stdin);
          freopen("out.txt", "w", stdout);
          #define er(...) cerr << __LINE__ << " <" << #__VA_ARGS__ << ">: ", dbg(__VA_ARGS__)
     #else
          #define er(...) 0
     #endif
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const ll mod = 1e9 + 7, mod2 = 1e9 + 9, maxn = 2e5 + 5, lg = 21, inf = ll(1e9) + 5;

ll pw(ll a, ll b){
     if(b == 0) return 1;
     ll k = pw(a, b>>1);
     return k*k*(b&1ll?a:1);
}

vector<int> adj[maxn];
ll par[maxn], H[maxn], C[maxn], nxt[maxn];
int h[maxn], cnt[maxn], top[maxn], st[maxn], en[maxn], t, eu[maxn];
ll dp[maxn];


int seg[maxn<<2];

int get(int l, int r, int x = 1, int lx = 0, int rx = t){
     if(l <= lx && r >= rx) return seg[x];
     int mid = (lx + rx)>>1;
     int res = -1;
     if(mid < r) res = get(l, r, x<<1|1, mid, rx);
     if(res + 1) return res;
     if(l < mid) return get(l, r, x<<1, lx, mid);
     return -1;
}

void upd(int i, bool act, int x = 1, int lx = 0, int rx = t){
     if(lx + 1 == rx){
          seg[x] = act? i: -1;
          return;
     }
     int mid = (lx + rx)>>1;
     if(i < mid) upd(i, act, x<<1, lx, mid);
     else upd(i, act, x<<1|1, mid, rx);
     seg[x] = max(seg[x<<1], seg[x<<1|1]);
}

ll fen[maxn];
ll getf(int i){
     ll res = 0;
     for(i++; i; i -= i&-i) res += fen[i];
     return res;
}
ll getf(int l, int r){
     return getf(r-1) - getf(l-1);
}
ll getu(int u){
     return getf(st[u], en[u]);
}
void updf(int i, ll k){
     for(i++; i < maxn; i += i&-i) fen[i] += k;
}

void dfs(int r, int p){
     par[r] = p;
     cnt[r] = 1;
     for(int c: adj[r]){
          h[c] = h[r] + 1;
          dfs(c, r);
          cnt[r] += cnt[c];
     }
}

void dfsHLD(int r, int tp){
     eu[t] = r;
     top[r] = tp, st[r] = t++;
     pp bst = {-1, -1};
     for(int c: adj[r]) bst = max(bst, {cnt[c], c});
     if(bst.ff + 1){
          dfsHLD(bst.ss, tp);
          for(int c: adj[r]) if(c - bst.ss) dfsHLD(c, c);
     }
     en[r] = t;
}

void add(int u){
     dp[u] = getu(u) + C[u];
     ll sm = C[u], cr = u;
     upd(st[u], true);
     u = par[u];
     if(u + 1){
          updf(st[u], sm);
     }
     while(u + 1){
          int x = get(st[top[u]], st[u] + 1);
          if(x + 1){
               x = eu[x];
               if(par[x] + 1) updf(st[par[x]], -sm);
               ll t = getu(x);
               if(t > dp[x]){
                    sm = t - dp[x];
                    upd(st[x], false);
                    u = par[x];
                    if(u + 1) updf(st[u], sm);
               } else break;
          } else u = par[top[u]];
     }
}

int main(){ IOS();  
     int n; cin >> n;
     ll sum = 0;
     rep(i,0,n){
          cin >> nxt[i] >> H[i] >> C[i];
          nxt[i]--;
          sum += C[i];
          if(i) assert(nxt[i] < i);
     }
     rep(i,1,n){
          adj[nxt[i]].pb(i);
     }
     dfs(0, -1);
     dfsHLD(0, 0);
     fill(seg, seg + (maxn<<2), -1);
     vector<int> srt(n);
     iota(all(srt), 0);
     sort(all(srt), [&](int i, int j){
          return pp(H[i], h[i]) > pp(H[j], h[j]);
     });
     rep(i,0,n){
          // er(i, srt[i]);
          add(srt[i]);
          // er(i);
     }
     // rep(i,0,n) er(i+1, dp[i], getu(i));
     // er(sum, max(getu(0), dp[0]));
     cout << sum - max(getu(0), dp[0]) << '\n';
     return 0;
}

Compilation message (stderr)

worst_reporter2.cpp: In function 'void add(int)':
worst_reporter2.cpp:110:20: warning: unused variable 'cr' [-Wunused-variable]
  110 |      ll sm = C[u], cr = u;
      |                    ^~
worst_reporter2.cpp: In function 'void IOS()':
worst_reporter2.cpp:24:18: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |           freopen("inp.txt", "r", stdin);
      |           ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
worst_reporter2.cpp:25:18: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |           freopen("out.txt", "w", stdout);
      |           ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 14
• Subtask 2: 0 / 65
• Subtask 3: 0 / 21