Submission #1018743

#	Time	Username	Problem	Language	Result	Execution time	Memory
1018743		FIFI_cpp	Collecting Stamps 3 (JOI20_ho_t3)	C++17	100 / 100	47 ms	37864 KiB

ho_t3

#include<bits/stdc++.h>
using namespace std;
const int N = 200;
const int inf = 1e9 + 10;
int v[N + 2];
int v2[N + 2];
int dp[N + 3][N + 3][N + 3][2];
int main(){
    int n,nr;
    int ans = 0;
    cin>>n>>nr;
    v[0] = 0;
    v2[0] = 100;
    for(int i = 1;i <= n;i++){
        cin>>v[i];
    }
    for(int i = 1;i <= n;i++){
        cin>>v2[i];
    }
    v[n + 1] = nr;
    v2[n + 1] = 100;
    n+=2;
    for(int i = 0;i <= n;i++){
        for(int j = 0;j <= i;j++){
            for(int k = 0;k <= i;k++){
                for(int p = 0;p <= 1;p++){
                    if(i == 0 && j == 0 && k == 0 && p == 0){
                        dp[i][j][k][p] = 0;
                    }else{
                        dp[i][j][k][p] = inf;
                        int leftid = n - 1 - (i - j);
                        int rightid = j;
                        int dist = v[rightid] + (nr - v[leftid]);
                        if(i == 0 || leftid <= rightid)continue;
                        if(p == 0){
                            if(leftid == n - 1)continue;
                            ///to leftside
                            ///from rightside
                            if(k != 0 && dist + dp[i - 1][j][k - 1][1] <= v2[leftid]){
                                dp[i][j][k][p] = min(dp[i][j][k][p],dist + dp[i - 1][j][k - 1][1]);
                            }else{
                                if(i != k)dp[i][j][k][p] = min(dp[i][j][k][p],dist + dp[i - 1][j][k][1]);
                            }
                            ///from leftside
                            if(k != 0 && dp[i - 1][j][k - 1][0] + v[leftid + 1] - v[leftid] <= v2[leftid]){
                                dp[i][j][k][p] = min(dp[i][j][k][p],dp[i - 1][j][k - 1][0] + v[leftid + 1] - v[leftid]);
                            }else{
                                if(i != k)dp[i][j][k][p] = min(dp[i][j][k][p],dp[i - 1][j][k][0] + v[leftid + 1] - v[leftid]);
                            }
                        }else{
                            if(j == 0 || rightid == n)continue;
                            ///to rightside
                            ///from leftside
                            if(k != 0 && dist + dp[i - 1][j - 1][k - 1][0] <= v2[rightid]){
                                dp[i][j][k][p] = min(dp[i][j][k][p],dist + dp[i - 1][j - 1][k - 1][0]);
                            }else{
                                if(i != k)dp[i][j][k][p] = min(dp[i][j][k][p],dist + dp[i - 1][j - 1][k][0]);
                            }
                            ///from rightside
                            if(k != 0 && (v[rightid] - v[rightid - 1]) + dp[i - 1][j - 1][k - 1][1] <= v2[rightid]){
                                dp[i][j][k][p] = min(dp[i][j][k][p],(v[rightid] - v[rightid - 1]) + dp[i - 1][j - 1][k - 1][1]);
                            }else{
                                if(i != k)dp[i][j][k][p] = min(dp[i][j][k][p],(v[rightid] - v[rightid - 1]) + dp[i - 1][j - 1][k][1]);
                            }
                        }
                        if(dp[i][j][k][p] != inf){
                            ans = max(ans,k);
                        }
                        //cout<<dp[i][j][k][p]<<' '<<i<<' '<<j<<' '<<k<<' '<<p<<' '<<dist<<' '<<leftid<<' '<<v[leftid + 1]<<' '<<v[leftid]<<' '<<(v[rightid] - v[rightid - 1])<<'\n';
                    }
                }
            }
        }
    }
    cout<<ans<<'\n';
    return 0;
}

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