Submission #769810

#	Time	Username	Problem	Language	Result	Execution time	Memory
769810		raysh07	Collecting Stamps 3 (JOI20_ho_t3)	C++17	100 / 100	103 ms	127484 KiB

ho_t3

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define INF (int)1e18
#define f first
#define s second

mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());

const int N = 201;
int n, l;
int x[N], t[N];
int dp[N][N][N][2]; 

int f(int x, int y){
    int ans = abs(x - y);
    ans = min(ans, abs(ans - l));
    return ans;
}

void ckmin(int &a, int b){
    a = min(a, b);
}

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];
    
    for (int i = 0; i < N; i++){
        for (int j = 0; j < N; j++){
            for (int k = 0; k < N; k++){
                dp[i][j][k][0] = dp[i][j][k][1] = INF;
            }
        }
    }
    
    int t1 = f(0, x[1]);
    dp[1][n + 1][t1 <= t[1]][0] = t1;
    int t2 = f(0, x[n]);
    dp[0][n][t2 <= t[n]][1] = t2;
    
    for (int sum = 2; sum <= n; sum++){
        for (int i = 0; i < sum; i++){
            int j = sum - 1 - i;
            j = n + 1 - j;
            
            for (int tk = 0; tk < sum; tk++){
                if (i != 0){
                    //last = 0
                    {
                        //go to i + 1
                        t1 = dp[i][j][tk][0] + f(x[i], x[i + 1]);
                        ckmin(dp[i + 1][j][tk + (t1 <= t[i + 1])][0], t1);
                    }
                    
                    {
                        //go to j - 1 
                        t1 = dp[i][j][tk][0] + f(x[i], x[j - 1]);
                        ckmin(dp[i][j - 1][tk + (t1 <= t[j - 1])][1], t1);
                    }
                }
                if (i + 1 != sum){
                    //last = 1
                    {
                        //go to i + 1
                        t1 = dp[i][j][tk][1] + f(x[j], x[i + 1]);
                        ckmin(dp[i + 1][j][tk + (t1 <= t[i + 1])][0], t1);
                    }
                    
                    {
                        //go to j - 1
                        t1 = dp[i][j][tk][1] + f(x[j], x[j - 1]);
                        ckmin(dp[i][j - 1][tk + (t1 <= t[j - 1])][1], t1);
                    }
                }
            }
        }
    }
    
    int ans = 0;
    
    for (int i = 0; i < N; i++){
        for (int j = 0; j < N; j++){
            for (int k = 0; k < N; k++){
                for (int l = 0; l < 2; l++){
                    if (dp[i][j][k][l] != INF){
                        ans = max(ans, k);
                    }
                }
            }
        }
    }
    
    cout << ans << "\n";
}

int32_t main() 
{
    auto begin = std::chrono::high_resolution_clock::now();
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
//    cin >> t;
    for(int i = 1; i <= t; i++) 
    {
        //cout << "Case #" << i << ": ";
        Solve();
    }
    auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n"; 
    return 0;
}

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