Submission #707538

#	Time	Username	Problem	Language	Result	Execution time	Memory
707538		Dan4Life	Collecting Stamps 3 (JOI20_ho_t3)	C++17	5 / 100	2 ms	3668 KiB

ho_t3

#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define mp make_pair
#define int long long
#define sz(a) (int)a.size()
const int mxN = (int)4e2+10;
const int LINF = (int)1e18;
pair<int,int> dp[mxN][mxN][2];
int x[mxN], t[mxN];

int32_t main() {
	ios_base::sync_with_stdio(false); cin.tie(0);
	int n, L; cin >> n >> L; int ans = 0;
	for(int i = 1; i <= n; i++) cin >> x[i], x[n+i+1]=x[i], x[i]-=L;
	for(int i = 1; i <= n; i++) cin >> t[i], t[n+i+1]=t[i];
	for(int i = 1; i <= 2*n; i++)
		for(int j = i; j <= 2*n; j++)
			for(int k = 0; k < 2; k++)
				dp[i][j][k] = mp(-LINF,LINF);
	dp[n+1][n+1][0]=dp[n+1][n+1][1]=mp(0,0);
	t[n+1] = -LINF;
	for(int len = 2; len <= n+1; len++){
		for(int l = 1; l <= n+1; l++){
			int r = l+len-1;
			dp[l][r][0] = max(
				mp(dp[l+1][r][0].fi+(dp[l+1][r][0].se+min(abs(x[l+1]-x[l]),L-abs(x[l+1]-x[l]))<=t[l]), 
				   dp[l+1][r][0].se+min(abs(x[l+1]-x[l]),L-abs(x[l+1]-x[l]))),
				mp(dp[l+1][r][1].fi+(dp[l+1][r][1].se+min(abs(x[r]-x[l]),L-abs(x[r]-x[l]))<=t[l]), 
				   dp[l+1][r][1].se+min(abs(x[r]-x[l]),L-abs(x[r]-x[l])))
			);
			dp[l][r][1] = max(
				mp(dp[l][r-1][0].fi+(dp[l][r-1][0].se+min(abs(x[l]-x[r]),L-abs(x[l]-x[r]))<=t[r]), 
				   dp[l][r-1][0].se+min(abs(x[l]-x[r]),L-abs(x[l]-x[r]))),
				mp(dp[l][r-1][1].fi+(dp[l][r-1][1].se+min(abs(x[r-1]-x[r]),L-abs(x[r-1]-x[r]))<=t[r]), 
				   dp[l][r-1][1].se+min(abs(x[r-1]-x[r]),L-abs(x[r-1]-x[r])))
			);
			if(len==n+1) ans = max({ans, dp[l][r][0].fi, dp[l][r][1].fi});
		}
	}
	cout << ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 75