Submission #254265

#	Time	Username	Problem	Language	Result	Execution time	Memory
254265		amoo_safar	Homecoming (BOI18_homecoming)	C++14	31 / 100	1088 ms	12152 KiB

homecoming

// Null
#include <bits/stdc++.h>

#ifndef safar
#include "homecoming.h"
#endif

using namespace std;

typedef long long ll;

const int NN = 2e6 + 10;
const ll Inf = 1e16;

ll dp[2][NN];

ll solve(int n, int k, int *A, int *B){

	ll ans = 0;
	ll S2 = 0;
	for(int i = 0; i < n; i++) S2 += A[i];
	for(int i = 0; i < n; i++) S2 -= B[i];

	ans = max(ans, S2);
	if(n == k){
		return ans;
	}
	for(int it = 0; it <= n; it ++){
	for(int j = 0; j + 1 < n; j ++) swap(A[j], A[j + 1]);
	for(int j = 0; j + 1 < n; j ++) swap(B[j], B[j + 1]);

	fill(dp[0], dp[0] + n + 1, -Inf);
	fill(dp[1], dp[1] + n + 1, -Inf);
	
	dp[0][0] = 0;
	ll Sm = B[0];
	for(int i = 1; i < n; i++){
		Sm += B[i];
		dp[0][i] = max(dp[0][i - 1], dp[1][i - 1]);
		if(i >= k){
			Sm -= B[i - k];
			dp[1][i] = max(dp[1][i - 1] - B[i] + A[i - k + 1], dp[0][i-k] + A[i - k + 1] - Sm);
		}
	}
	ans = max({ans, dp[0][n - 1], dp[1][n - 1]});
}
	return ans;
	/*
	fill(dp[0], dp[0] + n + 1, -Inf);
	fill(dp[1], dp[1] + n + 1, -Inf);
	dp[1][0] = 0;

	Sm = 0;
	for(int i = 0; i < k; i++) Sm += A[(n - i) % n];

	for(int i = 1; i < n; i++){
		Sm += A[i];
		Sm -= A[(i - k + n) % n];

		dp[1][i] = max(dp[0][i - 1], dp[1][i - 1]);
		
		dp[0][i] = max(dp[0][i - 1] + B[i] - A[i], dp[1][i - 1] + B[i] - Sm);
	}
	S2 = 0;
	for(int i = 0; i < n; i++) S2 += ((ll)A[i]) - B[i];

	ans = max(ans, S2 + max(dp[0][n - 1], dp[1][n - 1]));
	ans = max(ans, S2);
	return ans;
	*/
}

#ifdef safar
int Ai[3] = {0, 0, 1}, Bi[3] = {0, 2, 0};
int main(){
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	cout << solve(3, 2, Ai, Bi) << '\n';
	return 0;
}
#endif

• Subtask 1: 13 / 13
• Subtask 2: 18 / 18
• Subtask 3: 0 / 31
• Subtask 4: 0 / 38