Submission #749677

#	Time	Username	Problem	Language	Result	Execution time	Memory
749677		happypotato	Catfish Farm (IOI22_fish)	C++17	0 / 100	1126 ms	2097152 KiB

fish

#include "fish.h"
 
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int, int>
#define ff first
#define ss second
#define pb push_back
 
long long max_weights(int32_t n, int32_t m, vector<int32_t> X, vector<int32_t> Y,
					vector<int32_t> W) {
	
	for (int i = 0; i < m; i++) {
		X[i]++; Y[i]++;
	}

	int olda[n + 1][n + 1];
	for (int i = 0; i <= n; i++) {
		for (int j = 0; j <= n; j++) {
			olda[i][j] = 0;
		}
	}
	for (int i = 0; i < m; i++) {
		olda[X[i]][Y[i]] = W[i];
	}
	int oldps[n + 1][n + 1]; // ps[i][j] = a[i][1] + ... + a[i][j]
	for (int i = 1; i <= n; i++) {
		oldps[i][0] = 0;
		for (int j = 1; j <= n; j++) {
			oldps[i][j] = oldps[i][j - 1] + olda[i][j];
		}
	}

	vector<pii> a[n + 1], ps[n + 1];
	set<pii> critpts;
	for (int i = 1; i <= n; i++) {
		a[i].pb({0, 0});
		ps[i].pb({0, 0});
		critpts.insert({i, 0});
	}
	for (int i = 0; i < m; i++) {
		a[X[i]].pb({Y[i], W[i]});
		// critical points: (X[i] +- 1, Y[i]), (X[i], Y[i] - 1)
		if (X[i] > 1) {
			critpts.insert({X[i] - 1, Y[i]});
		}
		if (X[i] < n) {
			critpts.insert({X[i] + 1, Y[i]});
		}
		critpts.insert({X[i], Y[i] - 1});
	}
	for (int i = 1; i <= n; i++) {
		sort(a[i].begin(), a[i].end());
		for (pii &x : a[i]) {
			ps[i].pb({x.ff, ps[i].back().ss + x.ss});
		}
	}

	function<int(int, int)> GetPS = [&](int x, int y) -> int {
		if (ps[x].empty() || y < ps[x].front().ff) return 0;
		int lb = 0, rb = (int)(ps[x].size()) - 1;
		while (lb < rb) {
			int mid = (lb + rb + 1) >> 1;
			if (ps[x][mid].ff <= y) lb = mid;
			else rb = mid - 1;
		}
		return ps[x][lb].ss;
	};
	
	int olddp[2][n + 1][n + 1];
	// olddp[increasing][pos][height] = max ans from 1 to pos with pos getting height, height must be increasing
	for (int i = 0; i <= n; i++) {
		olddp[0][0][i] = olddp[1][0][i] = (i == 0 ? 0 : -1e18);
		olddp[0][1][i] = olddp[1][1][i] = 0;
	}
	int oldcur[n + 1];
	function<void(void)> resetoldcur = [&]() {
		for (int i = 0; i <= n; i++) oldcur[i] = 0;
	};

	vector<pii> dp[2][n + 1];
	for (int i = 0; i <= n; i++) {
		dp[0][0].pb({i, (i == 0 ? 0 : -1e18)});
		dp[1][0].pb({i, (i == 0 ? 0 : -1e18)});
		
		dp[0][1].pb({i, 0});
		dp[1][1].pb({i, 0});
	}
	for (pii x : critpts) {
		if (x.ff < 2) continue;
		dp[0][x.ff].pb({x.ss, 0});
		dp[1][x.ff].pb({x.ss, 0});
	}
	vector<pii> cur;
 
	for (int i = 2; i <= n; i++) {
		for (int j = 0; j <= n; j++) {
			olddp[0][i][j] = olddp[1][i][j] = 0;
		}
		sort(dp[0][i].begin(), dp[0][i].end());
		sort(dp[1][i].begin(), dp[1][i].end());
		// Case 0: height of i is 0
		resetoldcur();
		olddp[0][i][0] = max(olddp[0][i - 1][0], olddp[1][i - 1][0]);
		for (int j = 1; j <= n; j++) {
			olddp[0][i][0] = max(olddp[0][i][0], max(olddp[0][i - 1][j], olddp[1][i - 1][j]) + oldps[i][j]);
		}
		olddp[1][i][0] = olddp[0][i][0];

		// dp[flag][i][0].ff is always 0
		for (int j = 0; j < (int)(dp[0][i - 1].size()); j++) {
			dp[0][i][0].ss = max(dp[0][i][0].ss, dp[0][i - 1][j].ss + GetPS(i - 1, dp[0][i - 1][j].ff));
		}
		for (int j = 0; j < (int)(dp[1][i - 1].size()); j++) {
			dp[0][i][0].ss = max(dp[0][i][0].ss, dp[1][i - 1][j].ss + GetPS(i - 1, dp[1][i - 1][j].ff));
		}
		dp[1][i][0].ss = dp[0][i][0].ss;
 
		// Case 1: height of i-1 is 0
		// Case 1.1: height of i-2 <= height of i
		resetoldcur();
		oldcur[0] = olddp[0][i - 2][0];
		for (int j = 1; j <= n; j++) {
			oldcur[j] = max(oldcur[j - 1], max(olddp[0][i - 2][j], olddp[1][i - 2][j]));
		}
		for (int j = 0; j <= n; j++) {
			olddp[0][i][j] = max(olddp[0][i][j], oldcur[j] + oldps[i - 1][j]);
			olddp[1][i][j] = max(olddp[1][i][j], oldcur[j] + oldps[i - 1][j]);
		}
		// Case 1.2: height of i-2 >= height of i
		resetoldcur();
		oldcur[n] = olddp[0][i - 2][n] + oldps[i - 1][n];
		for (int j = n - 1; j >= 0; j--) {
			oldcur[j] = max(oldcur[j + 1], max(olddp[0][i - 2][j], olddp[1][i - 2][j]) + oldps[i - 1][j]);
		}
		for (int j = 0; j <= n; j++) {
			olddp[0][i][j] = max(olddp[0][i][j], oldcur[j]);
			olddp[1][i][j] = max(olddp[1][i][j], oldcur[j]);
		}
 
		// now height of i-1 > 0
		// Case 2: height of i-1 <= height of i
		resetoldcur();
		oldcur[1] = olddp[0][i - 1][1];
		for (int j = 2; j <= n; j++) {
			oldcur[j] = max(oldcur[j - 1] + olda[i - 1][j], olddp[0][i - 1][j]);
		}
		for (int j = 1; j <= n; j++) {
			olddp[0][i][j] = max(olddp[0][i][j], oldcur[j]);
		}
 
		// Case 3: height of i-1 >= height of i
		resetoldcur();
		oldcur[n] = max(olddp[0][i - 1][n], olddp[1][i - 1][n]);
		for (int j = n - 1; j >= 1; j--) {
			oldcur[j] = max(oldcur[j + 1] + olda[i][j + 1], max(olddp[0][i - 1][j], olddp[1][i - 1][j]));
		}
		for (int j = 1; j <= n; j++) {
			olddp[1][i][j] = max(olddp[1][i][j], oldcur[j]);
		}
	}
 
	int ans = max(dp[0][n][0].ss, dp[1][n][0].ss);
	for (int i = 1; i <= n; i++) {
		// cerr << olddp[0][n][i] << ' ' << olddp[1][n][i] << endl;
		ans = max(ans, max(olddp[0][n][i], olddp[1][n][i]));
	}
	return ans;
}
 
#undef int

• 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