Submission #423777

#	Time	Username	Problem	Language	Result	Execution time	Memory
423777		lyc	Table Tennis (info1cup20_tabletennis)	C++14	49 / 100	3082 ms	64564 KiB

tabletennis

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

#define TRACE(x) cerr << #x << " :: " << x << endl
#define _ << " " <<
#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()
#define FOR(i,a,b) for(int i=(a);i<=(b);++i)
#define RFOR(i,a,b) for(int i=(a);i>=(b);--i)

const int mxN = 150001;
const int mxK = 401;

int N, K;
int A[mxN];
int res[2005][2005], pa[2005][2005];

int dp(int l, int r) {
    if (l+1 == r) return 0;
    if (~res[l][r]) return res[l][r];
    res[l][r] = r-l-2;
    int a = l+1, b = r-1, c = 0;
    while (a < b && c <= K) {
        int cur = A[a]+A[b], tgt = A[l]+A[r];
        if (cur == tgt) {
            res[l][r] = dp(a,b)+c;
            break;
        }
        if (cur < tgt) ++a;
        else --b;
        ++c;
    }
    return res[l][r];
}

int main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    cin >> N >> K;
    FOR(i,1,N+K){
        cin >> A[i];
    }

    memset(res,-1,sizeof res);
    memset(pa,-1,sizeof pa);
    FOR(i,1,K+1){
        RFOR(j,N+K,N+i-1){
            //TRACE(i _ j _ dp(i,j) _ i-1 _ N+K-j);
            if (j-i+1-dp(i,j) >= N && dp(i,j) + (i-1) + (N+K-j) <= K) {
                //TRACE(i _ j);
                int l = i, r = j;
                int a = i+1, b = j-1;
                vector<int> ls = {l}, rs = {r};
                while (SZ(ls)+SZ(rs) < N) {
                    int cur = A[a]+A[b], tgt = A[l]+A[r];
                    if (cur == tgt) {
                        l = a, r = b;
                        ls.push_back(a);
                        rs.push_back(b);
                    }
                    if (cur < tgt) ++a;
                    else --b;
                }

                for (int& x : ls) cout << A[x] << ' ';
                reverse(ALL(rs));
                for (int& x : rs) cout << A[x] << ' ';
                return 0;
            }
        }
    }

    assert(false);
}

• Subtask 1: 11 / 11
• Subtask 2: 0 / 9
• Subtask 3: 0 / 14
• Subtask 4: 15 / 15
• Subtask 5: 9 / 9
• Subtask 6: 14 / 14
• Subtask 7: 0 / 15
• Subtask 8: 0 / 13