Submission #1057189

#	Time	Username	Problem	Language	Result	Execution time	Memory
1057189		dozer	Catfish Farm (IOI22_fish)	C++17	67 / 100	232 ms	70732 KiB

fish

#include "fish.h"
#include <bits/stdc++.h>
using namespace std;
#define sp " "
#define endl "\n"
#define pii pair<int, int>
#define st first
#define nd second
#define fileio() freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#define fastio() cin.tie(0), ios_base::sync_with_stdio(0)
#define pb push_back
#define ll long long
#define LL node * 2
#define RR node * 2 + 1
#define MAXN 300005

const int modulo = 1e9 + 7;
const ll INF = 2e18 + 7;


ll start[MAXN], dp[2][MAXN];
ll pref[MAXN], suff[MAXN];

vector<pii> fish[MAXN];


long long max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
	int n = N, m = M;
	vector<array<int, 3>> v;
	map<pii, int> done;
	for (int i = 0; i < m; i++) done[{X[i], Y[i]}] = 1;
	for (int i = 0; i < n; i++){
		if (done.count({i, 0}) == 0){
			X.pb(i), Y.pb(0), W.pb(0);
		}
	}

	m = X.size();
	for (int i = 0; i < m; i++) v.pb({X[i] + 1, Y[i], W[i]});
	sort(v.begin(), v.end());
    vector<int> x(m + 5), y(m + 5), w(m + 5);
    for (int i = 1; i <= m; i++) x[i] = v[i - 1][0], y[i] = v[i - 1][1], w[i] = v[i - 1][2];
    for (int i = 1; i <= m; i++) fish[x[i]].pb({y[i], i});

    vector<ll> pre(m + 5, 0);
	for (int i = 1; i <= m; i++) pre[i] = pre[i - 1] + w[i];

	for (int i = n; i >= 1; i--){
		start[i] = max(start[i + 1], start[i + 2] + pre[fish[i].back().nd] - pre[fish[i].front().nd - 1]);

		if (i == n) {
			for (auto j : fish[i]){
				int k = j.nd, b = j.st;
				pref[k] = -pre[k - 1];
				int tmp = lower_bound(fish[i - 1].begin(), fish[i - 1].end(), make_pair(b, 0)) - fish[i - 1].begin();
				tmp--;
				if (tmp >= 0){
					int to2 = fish[i - 1][tmp].nd;
					suff[k] = dp[1][k] + pre[to2];
				}

				for (int j = fish[i].front().nd + 1; j <= fish[i].back().nd; j++) pref[j] = max(pref[j - 1], pref[j]);
				for (int j = fish[i].back().nd - 1; j >= fish[i].front().nd; j--) suff[j] = max(suff[j], suff[j + 1]);
			}
			continue;
		}


		for (auto J = 0; J < fish[i].size(); J++){
			pii j = fish[i][J];
			int k = j.nd;
			int a = x[k], b = y[k];

			//todo : continue decreasing

			int to = lower_bound(fish[i + 1].begin(), fish[i + 1].end(), make_pair(b, 0)) - fish[i + 1].begin();
			to--;
			if (to >= 0){
				int to2 = fish[i + 1][to].nd;
				int gh = lower_bound(fish[i + 1].begin(), fish[i + 1].end(), make_pair(b + 1, 0)) - fish[i + 1].begin();
				gh--;
				if (gh >= 0){
					dp[0][k] = max(dp[0][k], pref[fish[i + 1][gh].nd] + pre[to2]);
				}
			}

			//todo : switch to increasing

			if (b == 0){
				dp[0][k] = max(dp[0][k], dp[1][fish[i + 1].front().nd]);
			}

			//////////////////////////////////////////

			//todo : continue increasing
			int gh = lower_bound(fish[i + 1].begin(), fish[i + 1].end(), make_pair(b, 0)) - fish[i + 1].begin();
			if (gh != fish[i + 1].size()){
				dp[1][k] = max(dp[1][k], suff[fish[i + 1][gh].nd] - pre[k - 1]);

			}

			//todo : connect to full column
			dp[1][k] = max(dp[1][k], start[i + 2] + pre[fish[i].back().nd] - pre[k - 1]);


			/////////////////////////////////////////
			pref[k] = dp[0][k] - pre[k - 1];
			int tmp = lower_bound(fish[i - 1].begin(), fish[i - 1].end(), make_pair(b, 0)) - fish[i - 1].begin();
			tmp--;
			if (tmp >= 0){
				int to2 = fish[i - 1][tmp].nd;
				suff[k] = dp[1][k] + pre[to2];
			}
		}
		

		for (int j = 0; j < fish[i].size(); j++){
			int curr = fish[i][j].nd;
			start[i] = max(start[i], dp[0][curr] + pre[fish[i].back().nd] - pre[curr - 1]);
		}

		for (int j = fish[i].front().nd + 1; j <= fish[i].back().nd; j++) pref[j] = max(pref[j - 1], pref[j]);
		for (int j = fish[i].back().nd - 1; j >= fish[i].front().nd; j--) suff[j] = max(suff[j], suff[j + 1]);
	}


	ll ans = start[2];
	for (int i = 1; i <= m; i++) {
		//cout<<i<<sp<<x[i]<<sp<<y[i]<<sp<<w[i]<<" : "<<dp[0][i]<<sp<<dp[1][i]<<endl;
		ans = max(ans, max(dp[0][i], dp[1][i]));
	}
	return ans;
}

/*

int main() {
	fileio();
	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;
}*/

Compilation message (stderr)

fish.cpp: In function 'long long int max_weights(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:69:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |   for (auto J = 0; J < fish[i].size(); J++){
      |                    ~~^~~~~~~~~~~~~~~~
fish.cpp:97:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   97 |    if (gh != fish[i + 1].size()){
      |        ~~~^~~~~~~~~~~~~~~~~~~~~
fish.cpp:72:8: warning: unused variable 'a' [-Wunused-variable]
   72 |    int a = x[k], b = y[k];
      |        ^
fish.cpp:117:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  117 |   for (int j = 0; j < fish[i].size(); j++){
      |                   ~~^~~~~~~~~~~~~~~~

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