Submission #1098632

#	Time	Username	Problem	Language	Result	Execution time	Memory
1098632		flyingkite	Collecting Stamps 3 (JOI20_ho_t3)	C++17	100 / 100	105 ms	143020 KiB

ho_t3

#include <bits/stdc++.h>
using namespace std;
 
#define ll long long
#define pll pair<long long, long long>
#define pb push_back
#define F first
#define S second  
#define all(x) (x).begin(), (x).end()
 
const ll N = 222;
const ll inf = 1e17;
const ll mod = 1e9 + 7;
const ll block = 350;
ll dp[N][N][N][2]; // dp[l][r][stamps][left/right]
ll n,L;
ll x[N], t[N];
void to_thic_cau(){
    cin >> n >> L;
    x[n+1] = 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 + 1;i++){
        for(int j = 0; j <= n + 1;j++){
            for(int k = 0; k <= n;k++) dp[i][j][k][0] = dp[i][j][k][1] = inf;
        }
    }
    dp[0][n+1][0][0] = 0;
    for(int i = 0; i <= n + 1;i++){
        for(int j = n + 1; j > i;j--){
            if(i == 0 && j == n + 1) continue;
            for(int k = 0; k <= n;k++){
                // TH ko pick
                if(i >= 1){
                    dp[i][j][k][0] = min(dp[i][j][k][0], dp[i-1][j][k][0] + x[i] - x[i-1]);
                    if(j <= n) dp[i][j][k][0] = min(dp[i][j][k][0], dp[i-1][j][k][1] + x[i] + L - x[j]);
                }
                if(j <= n){
                    dp[i][j][k][1] = min(dp[i][j][k][1], dp[i][j+1][k][1] + x[j+1] - x[j]);
                    dp[i][j][k][1] = min(dp[i][j][k][1], dp[i][j+1][k][0] + x[i] + L - x[j]);
                }
                if(k == 0) continue;
                // xet TH co pick (ben trai)
                if(i >= 1){
                    if(dp[i-1][j][k-1][0] + x[i] - x[i-1] <= t[i]){
                        dp[i][j][k][0] = min(dp[i][j][k][0], dp[i-1][j][k-1][0] + x[i] - x[i-1]);
                    }
                    if(j <= n){
                        if(dp[i-1][j][k-1][1] + x[i] + L - x[j] <= t[i]){
                            dp[i][j][k][0] = min(dp[i][j][k][0], dp[i-1][j][k-1][1] + x[i] + L - x[j]);
                        }
                    }
                }
                if(j <= n){
                    if(dp[i][j+1][k-1][1] + x[j+1] - x[j] <= t[j]){
                        dp[i][j][k][1] = min(dp[i][j][k][1], dp[i][j+1][k-1][1] + x[j+1] - x[j]);
                    } 
                    if(dp[i][j+1][k-1][0] + x[i] + L - x[j] <= t[j]){
                        dp[i][j][k][1] = min(dp[i][j][k][1], dp[i][j+1][k-1][0] + x[i] + L - x[j]);
                    }
                }
            }
        }
    }
    ll res = 0;
    for(int i = 0; i <= n;i++){
        for(int j = 0; j <= n + 1;j++){
            for(int k = 0; k <= n;k++){
                if(dp[i][j][k][0] < inf || dp[i][j][k][1] < inf) res = max(res, k * 1ll);
            }
        }
    }
    cout << res << '\n';
}
 
signed main()   
{  
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll tc = 1;
    //cin >> tc;
    while(tc--) to_thic_cau();
}

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