Submission #749789

#	Time	Username	Problem	Language	Result	Execution time	Memory
749789		happypotato	Catfish Farm (IOI22_fish)	C++17	9 / 100	610 ms	85652 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 {
		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<vector<pii>> dp[2];
	dp[0].resize(n + 1); dp[1].resize(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, 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, 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]);
		// }

		{
			cur.clear();
			for (int j = 0; j < (int)(dp[0][i - 2].size()); j++) {
				cur.pb({dp[0][i - 2][j].ff, max(dp[0][i - 2][j].ss, dp[1][i - 2][j].ss)});
			}
			for (int j = 1; j < (int)(cur.size()); j++) {
				cur[j].ss = max(cur[j].ss, cur[j - 1].ss);
			}
			int ptr = 0, curans = 0;
			for (int j = 0; j < (int)(dp[0][i].size()); j++) {
				while (ptr < (int)(cur.size()) && cur[ptr].ff <= dp[0][i][j].ff) {
					curans = max(curans, cur[ptr].ss);
					ptr++;
				}
				dp[0][i][j].ss = max(dp[0][i][j].ss, curans + GetPS(i - 1, j));
				dp[1][i][j].ss = max(dp[1][i][j].ss, curans + GetPS(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]);
		// }

		{
			cur.clear();
			for (int j = 0; j < (int)(dp[0][i - 2].size()); j++) {
				cur.pb({dp[0][i - 2][j].ff, max(dp[0][i - 2][j].ss, dp[1][i - 2][j].ss) + GetPS(i - 1, dp[0][i - 2][j].ff)});
			}
			for (int j = (int)(cur.size()) - 2; j >= 0; j--) {
				cur[j].ss = max(cur[j].ss, cur[j + 1].ss);
			}
			int ptr = (int)(cur.size()) - 1, curans = 0;
			for (int j = (int)(dp[0][i].size()) - 1; j >= 0; j--) {
				while (ptr >= 0 && cur[ptr].ff >= dp[0][i][j].ff) {
					curans = max(curans, cur[ptr].ss);
					ptr--;
				}
				dp[0][i][j].ss = max(dp[0][i][j].ss, curans);
				dp[1][i][j].ss = max(dp[1][i][j].ss, curans);
			}
		}
 
		// 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]);
		// }

		{
			cur.clear();
			int ptr = 1, curans = 0;
			for (int j = 1; j < (int)(dp[0][i].size()); j++) {
				curans += (GetPS(i - 1, dp[0][i][j].ff) - GetPS(i - 1, (j == 1 ? 1 : dp[0][i][j - 1].ff)));
				while (ptr < (int)(dp[0][i - 1].size()) && dp[0][i - 1][ptr].ff <= dp[0][i][j].ff) {
					curans = max(curans, dp[0][i - 1][ptr].ss + (GetPS(i - 1, dp[0][i][j].ff) - GetPS(i - 1, dp[0][i - 1][ptr].ff)));
					ptr++;
				}
				dp[0][i][j].ss = max(dp[0][i][j].ss, curans);
			}
		}
 
		// 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]);
		// }

		{
			cur.clear();
			int ptr = (int)(dp[1][i - 1].size()) - 1, curans = 0;
			for (int j = (int)(dp[1][i].size()) - 1; j >= 1; j--) {
				curans += (GetPS(i, (j + 1 == (int)(dp[1][i].size()) ? n : dp[1][i][j + 1].ff)) - GetPS(i, dp[1][i][j].ff));
				while (ptr >= 0 && dp[1][i - 1][ptr].ff >= dp[0][i][j].ff) {
					curans = max(curans, max(dp[0][i - 1][ptr].ss, dp[1][i - 1][ptr].ss) + (GetPS(i, dp[1][i - 1][ptr].ff) - GetPS(i, dp[1][i][j].ff)));
					ptr--;
				}
				dp[1][i][j].ss = max(dp[1][i][j].ss, curans);
			}
		}
	}
 
	// 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;

	// for (int i = 1; i <= n; i++) {
	// 	cerr << i << ": ";
	// 	for (pii &x : dp[1][i]) cerr << "(" << x.ff << ", " << x.ss << ") ";
	// 	cerr << endl;
	// }

	int ans = 0;
	for (pii &x : dp[0][n]) ans = max(ans, x.ss);
	for (pii &x : dp[1][n]) ans = max(ans, x.ss);
	return ans;
}
 
#undef int

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