Submission #702195

#	Time	Username	Problem	Language	Result	Execution time	Memory
702195		Josia	Sailing Race (CEOI12_race)	C++17	0 / 100	519 ms	16632 KiB

race

#include <bits/stdc++.h>

#define int int64_t

using namespace std;

vector<vector<bool>> graphRev;

int n;
bool type;


int DP[500][500][2][2];


void init() {
    for (int i=0; i<500; i++) {
        for (int j = 0; j<500; j++) {
            for (int k = 0; k<2; k++) {
                for (int l = 0; l<2; l++) {
                    DP[i][j][k][l] = -1;
                }
            }
        }
    }
}


int dp(int l, int r, bool pos, bool start) {
    if (DP[l][r][pos][start] != -1) return DP[l][r][pos][start];
    int res = 0;
    for (int v = (l+1)%n; v!=r; v=(v+1)%n) {
        if (!graphRev[pos?r:l][v]) continue;


        if (start) {
            // if (pos==0) {
                res = max(dp((l+n-1)%n, v, 1, 0)+1, res);
                res = max(dp(v, (r+1)%n, 0, 0)+1, res);
            // }
            // if (pos==1) {
            //     res = max(dp((l+n-1)%n, v, 1, 0)+1, res);
            //     res = max(dp(v, (r+1)%n, 0, 0)+1, res);
            // }
            continue;
        }

        // if (pos==0) {
            res = max(dp(l, v, 1, 0)+1, res);
            res = max(dp(v, r, 0, 0)+1, res);
        // }
        // if (pos==1) {
        //     res = max(dp(l, v, 1, 0)+1, res);
        //     res = max(dp(v, r, 0, 0)+1, res);
        // }
    }
    return DP[l][r][pos][start] = res;
}


signed main() {
    cin.tie(0);
    ios_base::sync_with_stdio(0);

    init();

    cin >> n;
    cin >> type;

    graphRev.assign(n,vector<bool>(n, 0));

    for (int i = 0; i<n; i++) {
        int x;
        cin >> x;
        while (x!=0) {
            graphRev[x-1][i]=1;
            // graphRev[i][x-1]=1;
            cin >> x;
        }
    }
    // for (auto i: graphRev) {
    //     for (int j: i) cerr << j << " ";
    //     cerr << "\n";
    // }
    // cerr << "\n";

    if (type == 0) {
        int res = 0;

        for (int i = 0; i<n; i++) {
            res = max(res, dp(i, i, 0, 1));
            // cerr << "---------\n";
        }

        cout << res << "\n";
        return 0;
    }

    assert(0);


    return 0;
}

• Subtask 1: 0 / 100