Submission #362234

#	Time	Username	Problem	Language	Result	Execution time	Memory
362234		knightron0	Collecting Stamps 3 (JOI20_ho_t3)	C++17	100 / 100	149 ms	130720 KiB

ho_t3

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

#define pb push_back
#define fr first
#define sc second
#define clr(a, x) memset(a, x, sizeof(a))
#define dbg(x) cout<<"("<<#x<<"): "<<x<<endl;
#define printvector(arr) for (auto it = arr.begin(); it != arr.end(); ++it) cout<<*it<<" "; cout<<endl;
#define all(v) v.begin(), v.end()
#define lcm(a, b) (a * b)/__gcd(a, b)
#define int long long int
#define printvecpairs(vec) for(auto it: vec) cout<<it.fr<<' '<<it.sc<<endl;
#define endl '\n'
#define float long double

const int MOD = 1e9 + 7;
const int INF = 2e15;
const int MAXN =205;

int n, m;
int a[MAXN], b[MAXN];

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    #ifdef LOCAL
    freopen("input.txt", "r", stdin);
    #endif
    cin>>n>>m;
    for(int i= 1;i<=n;i++){
    	cin>>a[i];
    }
    for(int i= 1;i<=n;i++){
    	cin>>b[i];
    }
    int dp[n+3][n+3][n+3][2];
    for(int i = 0;i<=n+1;i++){
        for(int j= n+1;j>=0;j--){
            for(int k = 0;k<=n+1;k++){
                dp[i][j][k][0] = dp[i][j][k][1] = INF;
            }
        }
    }
    // i = ith index from right
    // j = jth index from left
    // k = number of taken stamps
    dp[0][n+1][0][0] = 0;
    dp[0][n+1][0][1] = 0;
    int ans = 0;
    for(int i = 0;i<n;i++){
        for(int j= n+1;j>=1;j--){
            if(j <= i+1) break;
            for(int k = 0;k<=n;k++){   
                for(int p= 0;p<2;p++){
                    if(p == 0){
                        int last;
                        if(j == n+1) last = m;
                        else last = a[j];
                        int dist1 = a[i+1] - a[i];
                        int dist2 = a[i+1] + m - last;
                        int t1 = min(dp[i][j][k][0] + dist1, dp[i][j][k][1] + dist2);
                        int newk = k;
                        if(t1 <= b[i+1]) newk++;
                        dp[i+1][j][newk][0] = min(dp[i+1][j][newk][0], t1);
                        if(dp[i+1][j][newk][0] < INF){
                            ans = max(ans,newk);
                        }
                    } else {
                        int last;
                        if(j == n+1) last = m;
                        else last = a[j];
                        int dist1 = last - a[j-1];
                        int dist2 = a[i] + m - a[j-1];
                        int t2 = min(dp[i][j][k][1] + dist1, dp[i][j][k][0] + dist2);
                        int newk = k;
                        if(t2 <= b[j-1]) newk++;
                        dp[i][j-1][newk][1] = min(dp[i][j-1][newk][1], t2);
                        if(dp[i][j-1][newk][1] < INF){
                            ans = max(ans, newk);
                        }
                    }   
                
                }
            }
        }
    }
    cout<<ans<<endl;
    return 0;
}

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