Submission #703030

#	Time	Username	Problem	Language	Result	Execution time	Memory
703030		Josia	Sailing Race (CEOI12_race)	C++17	55 / 100	3055 ms	16236 KiB

race

#include <bits/stdc++.h>

#define int int64_t

using namespace std;

vector<vector<bool>> graph;
// vector<vector<bool>> graphRev;

int n;
bool type;


int DP1[500][500][2][2];
int DP2[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++) {
                    DP1[i][j][k][l] = -1;
                    DP2[i][j][k][l] = -1;
                }
            }
        }
    }
}


int dp1(int l, int r, bool pos, bool start) {
    if (DP1[l][r][pos][start] != -1) return DP1[l][r][pos][start];
    int res = 0;
    for (int v = (l+1)%n; v!=r; v=(v+1)%n) {
        if (!graph[pos?r:l][v]) continue;

        // if (pos==0) {
            res = max(dp1(l, v, 1, 0)+1, res);
            res = max(dp1(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);
        // }
    }
    // cerr << l << " " << r << " " << res << "\n";
    return DP1[l][r][pos][start] = res;
}

int dp2(int l, int r, bool pos, bool start) {
    if (DP2[l][r][pos][start] != -1) return DP2[l][r][pos][start];
    int res = -2;
    if ((l+1)%n==r) res = 0;
    for (int v = (l+1)%n; v!=r; v=(v+1)%n) {
        if (!graph[pos?r:l][v]) continue;

        if (pos==0) {
            // res = max(dp2(l, v, 1, 0)+1, res);
            res = max(dp2(v, r, 0, 0)+1, res);
        }
        if (pos==1) {
            res = max(dp2(l, v, 1, 0)+1, res);
            // res = max(dp(v, r, 0, 0)+1, res);
        }
    }
    // cerr << l << " " << r << " " << res << "\n";
    if (res == -1) res = -2;
    return DP2[l][r][pos][start] = res;
}


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

    init();

    cin >> n;
    cin >> type;

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

    for (int i = 0; i<n; i++) {
        int x;
        cin >> x;
        while (x!=0) {
            graph[i][x-1]=1;
            // graphRev[x-1][i]=1;
            cin >> x;
        }
    }


    int res = 0;
    int ind = -1;

    for (int i = 0; i<n; i++) {
        if (dp1(i, i, 0, 1) > res) {
            res = dp1(i, i, 0, 1);
            ind = i;
        }
    }

    if (type == 0) {
        cout << res << "\n" << ind+1 << "\n";
        return 0;
    }



    for (int i = 0; i<n; i++) {
        for (int j = 0; j<n; j++) {
            int tmp = 2;
            if (dp2((j+n-1)%n, i, 1, 1) == -2) continue;
            tmp += dp2((j+n-1)%n, i, 1, 1);
            int posFirst = -1;
            for (int k = i; k != j; k=(k+1)%n) {
                if (graph[k][i]) posFirst = k;
                // cerr << k << " " << i << "\n";
            }
            if (posFirst == -1) continue;

            int best = 0;
            for (int k = (i+1)%n; k != posFirst; k=(k+1)%n) {
                if (!graph[j][k]) continue;
                best = max(best, max(dp1(k, posFirst, 0, 1), dp1(i, k, 1, 1)));
            }

            tmp += best;

            // cerr << i << " " << j << " " << dp2((j+n-1)%n, i, 1, 1) << " " << tmp << "\n";

            if (tmp > res) {
                ind = posFirst;
                res = tmp;
            }
        }
    }

    // cerr << "-------\n";

    for (int i = 0; i<n; i++) {
        for (int j = 0; j<n; j++) {
            int tmp = 2;
            if (dp2((j+n-1)%n, i, 0, 1) == -2) continue;
            tmp += dp2((j+n-1)%n, i, 0, 1);
            int posFirst = -1;
            for (int k = j; k != i; k=(k+n-1)%n) {
                if (graph[k][j]) posFirst = k;
                // cerr << k << " " << i << "\n";
            }
            if (posFirst == -1) continue;

            int best = 0;
            for (int k = (j+n-1)%n; k != posFirst; k=(k+n-1)%n) {
                if (!graph[j][k]) continue;
                best = max(best, max(dp1(posFirst, k, 1, 1), dp1(k, j, 0, 1)));
            }

            tmp += best;

            // cerr << i << " " << j << " " << dp2((j+n-1)%n, i, 0, 1) << " " << tmp << "\n";

            if (tmp > res) {
                ind = posFirst;
                res = tmp;
            }
        }
    }






    cout << res << "\n" << ind+1 << "\n";


    return 0;
}

• Subtask 1: 55 / 100