Submission #680915

#	Time	Username	Problem	Language	Result	Execution time	Memory
680915		uylulu	Collecting Stamps 3 (JOI20_ho_t3)	C++17	100 / 100	249 ms	66892 KiB

ho_t3

#include <bits/stdc++.h>
using namespace std;

#define double long double
// #define int long long
#define endl "\n"

const int N = 200 + 3,oo = 1e9 + 5;

int dp[N + 1][N + 1][N + 1][2];

int x[N + 1],t[N + 1];

int n,len;

int f(int l,int r,int cnt,int side) {
    if(l == n + 1 && r == 0) {
        if(cnt != 0) {
            return oo;
        }
        return 0;
    }

    // cout<<cnt<<endl;

    if(dp[l][r][cnt][side] != -1) return dp[l][r][cnt][side];

    int res = oo;

    // cout<<l<<" "<<r<<" "<<cnt<<endl;

    if(side == 1) {
        if(r > 0) {
            res = min(res,f(l,r - 1,cnt,1) + (x[r] - x[r - 1]));
            res = min(res,f(l,r - 1,cnt,0) + (len - x[l]) + x[r]);
        }
    
        if(r > 0 && cnt > 0) {
            int tl = f(l,r - 1,cnt - 1,1);

            if(t[r] >= tl + (x[r] - x[r - 1])) {
                res = min(res,tl + x[r] - x[r - 1]);
            }

            tl = f(l,r - 1,cnt - 1,0);

            if(t[r] >= tl + (len - x[l]) + x[r]) {
                res = min(res,tl + (len - x[l]) + x[r]);
            }
        }
        return dp[l][r][cnt][side] = res;
    } else {
        if(l <= n) {
            res = min(res,f(l + 1,r,cnt,0) + abs(x[l] - x[l + 1]));
            res = min(res,f(l + 1,r,cnt,1) + (len - x[l]) + x[r]);
        }
        if(l <= n && cnt > 0) {
            int tl = f(l + 1,r,cnt - 1,0);

            if(t[l] >= tl + abs(x[l] - x[l + 1])) {
                res = min(res,tl + abs(x[l] - x[l + 1]));
            }
            tl = f(l + 1,r,cnt - 1,1);

            if(t[l] >= tl + (len - x[l]) + x[r]) {
                res = min(res,tl + (len - x[l]) + x[r]);
            }
        }
        return dp[l][r][cnt][side] = res;
    }
    return dp[l][r][cnt][side] = oo;
}

signed main() {
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    // freopen("in.txt","r",stdin);
    // freopen("out.txt","w",stdout);

    memset(dp,-1,sizeof(dp));

    cin>>n>>len;

    for(int i = 1;i <= n;i++) {
        cin>>x[i];
    }
    for(int i = 1;i <= n;i++) {
        cin>>t[i];
    }
    int res = 0;

    if(x[n] == len) {
        res++;
        n--;
    }
    x[0] = 0;
    x[n + 1] = len;

    int sum = 0;

    // cout<<f(0,4,7,1)<<endl;

    for(int i = 0;i <= n;i++) {
        for(int j = i + 1;j <= n + 1;j++) {
            for(int k = 0;k <= n;k++) {
                int asd = min(f(j,i,k,0),f(j,i,k,1));

                if(asd < oo) {
                    sum = max(sum,k);
                    // cout<<j<<" "<<i<<" "<<k<<endl;
                }

            }
        }
    }
    cout<<res + sum<<endl;

    return 0;
}       

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