Submission #1287885

#	Time	Username	Problem	Language	Result	Execution time	Memory
1287885		tminh	Collecting Stamps 3 (JOI20_ho_t3)	C++20	100 / 100	77 ms	130872 KiB

ho_t3

#include "bits/stdc++.h"
using namespace std;

#define task ""
#define ll long long
#define endl '\n'
#define fi first
#define se second
#define vall(a) (a).begin(), (a).end()
#define sze(a) (int)a.size()
#define pii pair<int, int>
#define pll pair<ll, ll>


#define ep emplace_back
#define pb push_back
#define pf push_front


const ll mod = 1e9 + 7;
const int N = 205;
const ll oo = 1e18;

bool START;

int n;

ll dp[N][N][N][2], pr[N], pl[N], tr[N], L, tl[N];
inline void solve() {
	pr[0] = pl[n] = 0;
	for (int i = 1; i <= n; ++i) pl[i - 1] = (L - pr[i]);
	for (int l = 0; l <= n; ++l) {
		for (int r = 0; r <= n; ++r) {
			for (int k = 0; k <= n; ++k) {
				dp[l][r][k][0] = dp[l][r][k][1] = oo;
			}
		}
	}
	dp[n][0][0][1] = dp[n][0][0][0] = 0;
	
	int ans = 0;
	for (int l = n; l >= 0; --l) {
		for (int r = 0; r <= l; ++r) {
			for (int k = 0; k <= n; ++k) {
				if (l < n) {
					dp[l][r][k][0] = min(dp[l][r][k][0], dp[l + 1][r][k][0] + (pl[l] - pl[l + 1]));
					if (k > 0 && dp[l + 1][r][k - 1][0] + (pl[l] - pl[l + 1]) <= tl[l]) {
						dp[l][r][k][0] = min(dp[l][r][k][0], dp[l + 1][r][k - 1][0] + (pl[l] - pl[l + 1]));
					}
					
					dp[l][r][k][0] = min(dp[l][r][k][0], dp[l + 1][r][k][1] + pr[r] + pl[l]);
					if (k > 0 && dp[l + 1][r][k - 1][1] + pr[r] + pl[l] <= tl[l]) {
						dp[l][r][k][0] = min(dp[l][r][k][0], dp[l + 1][r][k - 1][1] + pr[r] + pl[l]);
					}
				}
				if (r > 0) {
					dp[l][r][k][1] = min(dp[l][r][k][1], dp[l][r - 1][k][1] + (pr[r] - pr[r - 1]));
					if (k > 0 && dp[l][r - 1][k - 1][1] + (pr[r] - pr[r - 1]) <= tr[r]) {
						dp[l][r][k][1] = min(dp[l][r][k][1], dp[l][r - 1][k - 1][1] + (pr[r] - pr[r - 1]));
					}
					
					dp[l][r][k][1] = min(dp[l][r][k][1], dp[l][r - 1][k][0] + pr[r] + pl[l]);
					if (k > 0 && dp[l][r - 1][k - 1][0] + pr[r] + pl[l] <= tr[r]) {
						dp[l][r][k][1] = min(dp[l][r][k][1], dp[l][r - 1][k - 1][0] + pr[r] + pl[l]);
					}
				}
				if (dp[l][r][k][0] < oo) ans = max(ans, k);
				if (dp[l][r][k][1] < oo) ans = max(ans, k);
			}
		}
	}
	cout << ans;
}


inline void input() {
    cin >> n >> L;
    for (int i = 1; i <= n; ++i) cin >> pr[i];
    for (int i = 1; i <= n; ++i) {
    	cin >> tr[i];
    	tl[i - 1] = tr[i];
    }
    return solve();
}
bool END;

int main() {
    if(fopen(task ".inp", "r")) {
        freopen(task ".inp", "r", stdin);
        freopen(task ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);

    input();
    
    
    cerr << endl << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << 's' << endl;
    cerr << "Memory: " << fabs ((&END - &START)) / 1048576.0 << "MB\n";
    return 0;
}
//2911

Compilation message (stderr)

ho_t3.cpp: In function 'int main()':
ho_t3.cpp:89:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |         freopen(task ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
ho_t3.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |         freopen(task ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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