| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 678827 | pls33 | Catfish Farm (IOI22_fish) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#ifndef _AAAAAAAAA
#include "fish.h"
#endif
using namespace std;
using namespace __gnu_pbds;
#pragma region dalykai
using p32 = pair<int, int>;
using p32u = pair<uint32_t, uint32_t>;
using p64 = pair<int64_t, int64_t>;
using p64u = pair<uint64_t, uint64_t>;
using vi16 = vector<int16_t>;
using vi16u = vector<uint16_t>;
using vi32 = vector<int>;
using vi32u = vector<uint32_t>;
using vi64 = vector<int64_t>;
using vi64u = vector<uint64_t>;
using vp32 = vector<p32>;
using vp32u = vector<p32u>;
using vp64 = vector<p64>;
using vp64u = vector<p64u>;
using vvi32 = vector<vi32>;
using vvi32u = vector<vi32u>;
using vvi64 = vector<vi64>;
using vvi64u = vector<vi64u>;
using vvp32 = vector<vp32>;
using vvp32u = vector<vp32u>;
using vvp64 = vector<vp64>;
using vvp64u = vector<vp64u>;
#pragma endregion
using map_t = gp_hash_table<int64_t, int64_t>;
const auto __comp = [](p64 a, p64 b)
{
return a.first < b.first;
};
struct node_t
{
int64_t val;
p32 range;
node_t *left, *right;
node_t(p32 r)
{
val = 0;
range = r;
left = nullptr;
right = nullptr;
}
void update()
{
if (!right || range.second - range.first == 1)
{
return;
}
val = max(left->val, right->val);
}
void expand()
{
if (range.second - range.first == 1 || right)
{
return;
}
int mid = midpoint(range.first, range.second);
left = new node_t({range.first, mid});
right = new node_t({mid, range.second});
}
int contains(p32 query)
{
if (query.first >= range.second || query.second <= range.first)
{
return 0;
}
if (range.first >= query.first && range.second <= query.second)
{
return 1;
}
return 2;
}
};
void update(node_t *node, int64_t val, p32 dest)
{
if (!node || !node->contains(dest))
{
return;
}
if (node->contains(dest) == 1)
{
node->val = max(node->val, val);
return;
}
node->expand();
update(node->left, val, dest);
update(node->right, val, dest);
node->update();
}
int64_t query(node_t *node, p32 dest)
{
if (!node || !node->contains(dest))
{
return 0;
}
if (node->contains(dest) == 1)
{
return node->val;
}
return max(query(node->left, dest),
query(node->right, dest));
}
void assign_max(int64_t val, int64_t &v)
{
v = max(v, val);
}
int64_t weight_sum(int l, int r, vp64 &prefix)
{
if (l == -1 || !prefix.size() || r < prefix[0].first)
{
return 0;
}
auto hi = lower_bound(prefix.begin(), prefix.end(), p64{r, INT64_MAX}, __comp);
if (hi == prefix.end())
{
hi--;
}
int64_t sum = hi->second;
if (l)
{
auto lo = lower_bound(prefix.begin(), prefix.end(), p64{l - 1, INT64_MAX}, __comp);
if (lo != hi)
{
sum -= lo->second;
}
}
return sum;
}
int64_t new_weight(p32 lhs, p32 rhs, vvp64 &prefix)
{
int64_t left = rhs.first > 0
? weight_sum(0, rhs.second, prefix[rhs.first - 1])
: 0;
int64_t right = (rhs.first + 1 < (int)prefix.size())
? weight_sum(0, rhs.second, prefix[rhs.first + 1])
: 0;
if (lhs.first == -1)
{
return left + right;
}
if (rhs.first - lhs.first > 2)
{
return left + right;
}
if (rhs.first - lhs.first == 2)
{
if (lhs.second >= rhs.second)
{
return right;
}
left -= weight_sum(0, lhs.second, prefix[rhs.first - 1]);
return left + right;
}
if (lhs.second > rhs.second)
{
left = -weight_sum(0, rhs.second, prefix[rhs.first]);
return left + right;
}
left -= weight_sum(0, lhs.second, prefix[rhs.first]) +
weight_sum(0, lhs.second, prefix[rhs.first - 1]);
return left + right;
}
long long max_weights(int N, int M,
std::vector<int> X,
std::vector<int> Y,
std::vector<int> W)
{
vp32 fish;
vvp64 prefix(N);
for (int i = 0; i < M; i++)
{
prefix[X[i]].emplace_back(Y[i], W[i]);
if (X[i])
{
fish.push_back({X[i] - 1, Y[i]});
}
if (X[i] < N - 1)
{
fish.push_back({X[i] + 1, Y[i]});
}
}
for (auto &row : prefix)
{
sort(row.begin(), row.end(), __comp);
for (int i = 1; i < (int)row.size(); i++)
{
row[i].second += row[i - 1].second;
}
}
sort(fish.begin(), fish.end());
auto it = unique(fish.begin(), fish.end());
fish.erase(it, fish.end());
map_t decrease({}, {}, {}, {}, {1ULL << 17});
map_t increase({}, {}, {}, {}, {1ULL << 17});
vp32 check;
node_t *fish_count = new node_t({0, N});
for (auto &f : fish)
{
int64_t initial = new_weight(p32(-1, -1), f, prefix);
if (f.first > 2)
{
initial += query(fish_count, {0, f.first - 2});
}
auto &f_inc = increase[f.first * N + f.second];
auto &f_dec = decrease[f.first * N + f.second];
assign_max(initial, f_inc);
assign_max(initial, f_dec);
check.push_back(f);
for (int cur = (int)check.size() - 2; cur >= 0; cur--)
{
auto &[i, j] = check[cur];
auto &inc = increase[i * N + j];
auto &dec = decrease[i * N + j];
if (f.first - i > 3)
{
break;
}
if (i == f.first)
{
continue;
}
int64_t prev = new_weight(p32(i, j), f, prefix);
if (i == f.first - 1)
{
if (j < f.second)
{
assign_max(prev + inc, f_inc);
}
else
{
assign_max(prev + dec, f_dec);
}
}
else
{
prev += max(inc, dec);
assign_max(prev, f_inc);
assign_max(prev, f_dec);
}
}
update(fish_count,
max(f_inc, f_dec),
{f.first, f.first + 1});
}
return fish_count->val;
}
#ifdef _AAAAAAAAA
int main()
{
freopen("fish.in", "r", stdin);
#ifndef __linux__
atexit([]()
{
freopen("con", "r", stdin);
system("pause"); });
#endif
int N, M;
assert(2 == scanf("%d %d", &N, &M));
std::vector<int> X(M), Y(M), W(M);
for (int i = 0; i < M; ++i)
{
assert(3 == scanf("%d %d %d", &X[i], &Y[i], &W[i]));
}
long long result = max_weights(N, M, X, Y, W);
printf("%lld\n", result);
return 0;
}
#endif