Submission #1282795

#	Time	Username	Problem	Language	Result	Execution time	Memory
1282795		trvhung	Collecting Stamps 3 (JOI20_ho_t3)	C++20	100 / 100	128 ms	135316 KiB

ho_t3

#include <bits/stdc++.h>
// #include <ext/rope>
// #include <ext/pb_ds/assoc_container.hpp>

// using namespace __gnu_pbds;
// using namespace __gnu_cxx;
using namespace std;

// #define   ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define            ll long long
#define           ull unsigned long long
#define            ld long double
#define            pb push_back
#define  bit(mask, i) ((mask >> i) & 1)
#define            el '\n'
#define             F first
#define             S second

template <class X, class Y> bool maximize(X &x, const Y &y) { return (x < y ? x = y, 1 : 0); }
template <class X, class Y> bool minimize(X &x, const Y &y) { return (x > y ? x = y, 1 : 0); }

const int INF = 1e9;
const ll LINF = 1e18;
const int MOD = 1e9 + 7;
const int MULTI = 0;
const ld eps = 1e-9;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0}; // R D L U
const int ddx[4] = {-1, 1, 1, -1}, ddy[4] = {1, 1, -1, -1}; // UR DR DL UL
const char cx[4] = {'R', 'D', 'L', 'U'};
const ll base = 31;
const int nMOD = 2;
const ll mods[] = {(ll)1e9 + 10777, (ll)1e9 + 19777, (ll)1e9 + 3, (ll)1e9 + 3777};

const int N = 2e2 + 5;
int n, l, x[N], t[N];
ll dp[N][N][N][2];

int DIST(int i, int j) {
	if (i == n + 1) return min(x[j], l - x[j]);
	if (j == n + 1) return min(x[i], l - x[i]);

	if (i > j) swap(i, j);
	return min(x[j] - x[i], l - x[j] + x[i]);
}

void solve() {
	cin >> n >> l;
	for (int i = 1; i <= n; ++i)
		cin >> x[i];
	for (int i = 1; i <= n; ++i)
		cin >> t[i];

	memset(dp, 0x3f, sizeof(dp));
	dp[n + 1][n + 1][0][0] = dp[n + 1][n + 1][0][1] = 0;

	for (int len = 1; len <= n; ++len)
		for (int i = 1; i <= n + 1; ++i) 
			for (int score = 0; score <= n; ++score) {
				int j;
				if (i == n + 1)
					j = (len == 1 ? n + 1 : len - 1);
				else if (i + len - 1 <= n + 1)
					j = i + len - 1;
				else
					j = i + len - n - 2;

				int prv = (i == 1 ? n + 1 : i - 1);
				int nxt = (j == n + 1 ? 1 : j + 1);

				if (dp[i][j][score][0] < LINF) {
					int dist = DIST(i, prv);
					int add = (dp[i][j][score][0] + dist <= t[prv]);
					minimize(dp[prv][j][score + add][0], dp[i][j][score][0] + dist);

					dist = DIST(i, nxt);
					add = (dp[i][j][score][0] + dist <= t[nxt]);
					minimize(dp[i][nxt][score + add][1], dp[i][j][score][0] + dist);
				}

				if (dp[i][j][score][1] < LINF) {
					int dist = DIST(j, nxt);
					int add = (dp[i][j][score][1] + dist <= t[nxt]);
					minimize(dp[i][nxt][score + add][1], dp[i][j][score][1] + dist);

					dist = DIST(j, prv);
					add = (dp[i][j][score][1] + dist <= t[prv]);
					minimize(dp[prv][j][score + add][0], dp[i][j][score][1] + dist);
				}
			}

	int res = 0;
	for (int i = 1; i <= n + 1; ++i)
		for (int j = 1; j <= n + 1; ++j)
			for (int score = 0; score <= n; ++score)
				for (int t = 0; t < 2; ++t)
					if (dp[i][j][score][t] < LINF)
						maximize(res, score);

	cout << res;
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    if (!MULTI) solve();
    else {
        int test; cin >> test;
        while (test--) solve();
    }
    
    return 0;
}

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