Submission #1039114

#	Time	Username	Problem	Language	Result	Execution time	Memory
1039114		Otalp	Collecting Stamps 3 (JOI20_ho_t3)	C++14	100 / 100	278 ms	580876 KiB

ho_t3

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define pb push_back
#define ff first
#define ss second

const ll INF = 1e9 + 5;

pii a[501];
ll dp[501][501][501][2];

void solve(){
    int n, L;
    cin>>n;
    cin>>L;
    a[n + 1] = {0, 0};
    for(int i=1; i<=n; i++){
        cin>>a[i+n + 1].ff;
    }
    for(int i=1; i<=n; i++){
        cin>>a[i+n+1].ss;
    }
    for(int i=n; i>=1; i--){
        a[i] = {a[i + n + 1].ff - L, a[i+n+1].ss};
    }
    for(int i=1; i<=n + n + 1; i++){
        for(int r = n + n + 1; r>=i; r--){
            for(int k=0; k<=n; k++){
                dp[i][r][k][0] = dp[i][r][k][1] = INF;
            }
        }
    }

    dp[n+1][n+1][0][0] = dp[n+1][n+1][0][1] = 0;
    int ans = 0;
    for(int d=2; d<=n+1; d++){
        for(int l=1; l<=2 * n + 1 - d + 1; l++){
            int r = l + d - 1;
            for(int k=0; k<=n; k++){
                ll g;
                g = dp[l][r-1][k][0] + a[r].ff - a[l].ff;
                if(g <= a[r].ss){
                    dp[l][r][k+1][1] = min(dp[l][r][k+1][1], g);
                }
                dp[l][r][k][1] = min(dp[l][r][k][1], g);

                g = dp[l][r-1][k][1] + a[r].ff - a[r-1].ff;
                if(g <= a[r].ss){
                    dp[l][r][k+1][1] = min(dp[l][r][k+1][1], g);
                }
                dp[l][r][k][1] = min(dp[l][r][k][1], g);

                g = dp[l+1][r][k][0] + a[l+1].ff - a[l].ff;
                if(g <= a[l].ss){
                    dp[l][r][k+1][0] = min(dp[l][r][k+1][0], g);
                }
                dp[l][r][k][0] = min(dp[l][r][k][0], g);

                g = dp[l+1][r][k][1] + a[r].ff - a[l].ff;
                if(g <= a[l].ss){
                    dp[l][r][k+1][0] = min(dp[l][r][k+1][0], g);
                }
                dp[l][r][k][0] = min(dp[l][r][k][0], g);
            }
        }
    }
    for(int i=1; i<=n + n + 1; i++){
        for(int r = n + n + 1; r>=i; r--){
            for(int k=0; k<=n; k++){
                if(dp[i][r][k][0] < INF or dp[i][r][k][1] < INF){
                    //cout<<i<<' '<<r<<' '<<k<<' '<<min(dp[i][r][k][1], dp[i][r][k][0])<<'\n';
                    ans = max(ans, k);
                }
            }
        }
    }
    cout<<ans;
    




    


}

signed main(){
    solve();
}

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