Submission #749305

#	Time	Username	Problem	Language	Result	Execution time	Memory
749305		happypotato	Catfish Farm (IOI22_fish)	C++17	0 / 100	764 ms	2097152 KiB

fish

#include "fish.h"
 
#include <bits/stdc++.h>
using namespace std;
#define int long long
 
long long max_weights(int32_t n, int32_t m, vector<int32_t> X, vector<int32_t> Y,
					vector<int32_t> W) {
	
	int a[n + 1][n + 1];
	for (int i = 0; i <= n; i++) {
		for (int j = 0; j <= n; j++) {
			a[i][j] = 0;
		}
	}
	for (int i = 0; i < m; i++) {
		X[i]++; Y[i]++;
		a[X[i]][Y[i]] = W[i];
	}
	// for (int i = 1; i <= n; i++) {
	// 	for (int j = 1; j <= n; j++) {
	// 		cerr << a[i][j] << ' ';
	// 	}
	// 	cerr << endl;
	// }
	// cerr << endl;
	int ps[n + 1][n + 1]; // ps[i][j] = a[i][1] + ... + a[i][j]
	for (int i = 1; i <= n; i++) {
		ps[i][0] = 0;
		for (int j = 1; j <= n; j++) {
			ps[i][j] = ps[i][j - 1] + a[i][j];
		}
	}
	
	int dp[2][n + 1][n + 1];
	// dp[increasing][pos][height] = max ans from 1 to pos with pos getting height, height must be increasing
	for (int i = 0; i <= n; i++) {
		dp[0][0][i] = dp[1][0][i] = (i == 0 ? 0 : -1e18);
		dp[0][1][i] = dp[1][1][i] = 0;
	}
	int cur[n + 1];
	function<void(void)> resetcur = [&]() {
		for (int i = 0; i <= n; i++) cur[i] = 0;
	};
 
	for (int i = 2; i <= n; i++) {
		for (int j = 0; j <= n; j++) {
			dp[0][i][j] = dp[1][i][j] = 0;
		}
		// Case 0: height of i is 0
		resetcur();
		dp[0][i][0] = max(dp[0][i - 1][0], dp[1][i - 1][0]);
		for (int j = 1; j <= n; j++) {
			dp[0][i][0] = max(dp[0][i][0], max(dp[0][i - 1][j], dp[1][i - 1][j]) + ps[i][j]);
		}
		dp[1][i][0] = dp[0][i][0];
 
		// Case 1: height of i-1 is 0
		// Case 1.1: height of i-2 <= height of i
		resetcur();
		cur[0] = dp[0][i - 2][0];
		for (int j = 1; j <= n; j++) {
			cur[j] = max(cur[j - 1], max(dp[0][i - 2][j], dp[1][i - 2][j]));
		}
		for (int j = 0; j <= n; j++) {
			dp[0][i][j] = max(dp[0][i][j], cur[j] + ps[i - 1][j]);
			dp[1][i][j] = max(dp[1][i][j], cur[j] + ps[i - 1][j]);
		}
		// Case 1.2: height of i-2 >= height of i
		resetcur();
		cur[n] = dp[0][i - 2][n] + ps[i - 1][n];
		for (int j = n - 1; j >= 0; j--) {
			cur[j] = max(cur[j + 1], max(dp[0][i - 2][j], dp[1][i - 2][j]) + ps[i - 1][j]);
		}
		for (int j = 0; j <= n; j++) {
			dp[0][i][j] = max(dp[0][i][j], cur[j]);
			dp[1][i][j] = max(dp[1][i][j], cur[j]);
		}
 
		// now height of i-1 > 0
		// Case 2: height of i-1 <= height of i
		resetcur();
		cur[1] = dp[0][i - 1][1];
		for (int j = 2; j <= n; j++) {
			cur[j] = max(cur[j - 1] + a[i - 1][j], dp[0][i - 1][j]);
		}
		for (int j = 1; j <= n; j++) {
			dp[0][i][j] = max(dp[0][i][j], cur[j]);
		}
 
		// Case 3: height of i-1 >= height of i
		resetcur();
		cur[n] = dp[1][i - 1][n];
		for (int j = n - 1; j >= 1; j--) {
			cur[j] = max(cur[j + 1] + a[i][j + 1], dp[1][i - 1][j]);
		}
		for (int j = 1; j <= n; j++) {
			dp[1][i][j] = max(dp[1][i][j], cur[j]);
		}
		dp[1][i][0] = max(dp[1][i][0], dp[1][i][1] + a[i][1]);
	}
 
	int ans = 0;
	for (int i = 0; i <= n; i++) {
		// cerr << dp[0][n][i] << ' ' << dp[1][n][i] << endl;
		ans = max(ans, max(dp[0][n][i], dp[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