Submission #892887

#	Time	Username	Problem	Language	Result	Execution time	Memory
892887		Trisanu_Das	Catfish Farm (IOI22_fish)	C++17	0 / 100	47 ms	10960 KiB

fish

#include <bits/stdc++.h>
#include "fish.h"
using namespace std;
#define ll long long
#define ff first
#define ss second
 
int n; //global var for storing N
vector<pair<int, int> > fishes[100005]; //Stores the fishes in each row
 
struct SegmentTree{
  ll tree[1 << 18];
  void init(){
    memset(tree, 0xcf, sizeof(tree));
  }
  void upd(int idx, int s, int e, int l, int r, ll val){
    if(e < l || r < s) return;
    if(l <= s && e <= r){
      tree[idx] = max(tree[idx], val);
      return;
    }
    int mid = (s + e) / 2;
    upd(2 * idx, s, mid, l, r, val);
    upd(2 * idx + 1, mid + 1, e, l, r, val);
  }
  ll qry(int idx, int s, int e, int x){
    if(s == e) return tree[idx];
    int mid = (s + e) / 2;
    if(x <= mid) return qry(2 * idx, s, mid, x);
    return qry(2 * idx + 1, mid + 1, e, x);
  }
}st_up, st_down;
 
ll max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W){
  n = N;
  for(int i = 0; i < M; i++) fishes[X[i] + 1].push_back({Y[i] + 1, W[i]});
  ll till_now = 0;
  st_down.init();
  for(int i = 1; i <= n; i++){
    sort(fishes[i].begin(), fishes[i].end());
    for(auto [j, w] : fishes[i]) st_up.upd(1, 0, n + 1, j + 1, n + 1, st_up.qry(1, 0, n + 1, j) + w);
    reverse(fishes[i].begin(), fishes[i].end());
    for(auto [j, w] : fishes[i]) st_down.upd(1, 0, n + 1, 0, j - 1, st_down.qry(1, 0, n + 1, j) + w);
    ll u_res = st_up.qry(1, 0, n + 1, n + 1), d_res = st_down.qry(1, 0, n + 1, 0);
    st_up.upd(1, 0, n + 1, 0, n + 1, d_res);
    st_down.upd(1, 0, n + 1, 0, n + 1, till_now);
    till_now = max(u_res, d_res);
  }
  return st_down.qry(1, 0, n + 1, 0);
}

• Subtask 1: 0 / 3
• Subtask 2: 0 / 6
• Subtask 3: 0 / 9
• Subtask 4: 0 / 14
• Subtask 5: 0 / 21
• Subtask 6: 0 / 17
• Subtask 7: 0 / 14
• Subtask 8: 0 / 16