Submission #982613

# Submission time Handle Problem Language Result Execution time Memory
982613 2024-05-14T13:38:48 Z PanosPask Sailing Race (CEOI12_race) C++14
40 / 100
3000 ms 4956 KB
/*This problem needs arrays instad of vectors due to
extremely tight ML and TL*/

#include <bits/stdc++.h>
#define pb push_back
#define MOD(var, M) (((var) >= (M)) ? ((var) - M) : (var))

using namespace std;

const int MAXN = 500;
const int INF = 1e9;

int N, K;
bool stage[MAXN][MAXN];

vector<vector<int>> adj_list;

// dp[l][r][k]:  Maximum number of stages if enclosed by l, r
// and being in the stages such that l < s < r'
// Where r' = l > r ? r = r + N : r

// k == 0: Starting in l
// k == 1: Starting in r
int dp[MAXN][MAXN][2];

// Before the intersection with the first stage
// You can only choose one way to follow
// Either from l to r or from r to l
int bef[MAXN][MAXN][2];

int main(void)
{
    scanf("%d %d", &N, &K);

    adj_list.resize(N);

    for (int i = 0; i < N; i++) {
        int v;
        scanf("%d", &v);

        while (v != 0) {
            v--;
            stage[i][v] = true;
            adj_list[i].pb(v);
            adj_list[i].pb(v + N);
            scanf("%d", &v);
        }
    }

    for (int len = 1; len <= N; len++) {
        for (int l = 0; l < N; l++) {
            int r_actual = l + len - 1;
            int r = MOD(r_actual, N);

            bef[l][r][0] = bef[l][r][1] = -INF;

            for (int i_actual = l + 1; i_actual < r_actual; i_actual++) {
                int i = MOD(i_actual, N);

                dp[l][r][0] = max(dp[l][r][0], dp[l][i][0]);
                dp[l][r][1] = max(dp[l][r][1], dp[i][r][1]);

                if (bef[l][i][0] != -INF && bef[i][r][0] != -INF) {
                    bef[l][r][0] = max(bef[l][r][0], bef[l][i][0] + bef[i][r][0]);
                }
                if (bef[l][i][1] != -INF && bef[i][r][1] != -INF) {
                    bef[l][r][1] = max(bef[l][r][1], bef[l][i][1] + bef[i][r][1]);
                }

                if (stage[l][i]) {
                    dp[l][r][0] = max(dp[l][r][0], 1 + dp[i][r][0]);
                }
                if (stage[r][i]) {
                    dp[l][r][1] = max(dp[l][r][1], 1 + dp[l][i][1]);
                }
            }

            if (stage[l][r]) {
                int res = 1 + dp[MOD(l + 1, N)][r][1];
                if (res >= dp[l][r][0]) {
                    dp[l][r][0] = res;
                }

                bef[l][r][0] = max(bef[l][r][0], 1);
            }
            if (stage[r][l]) {
                int res = 1 + dp[l][MOD(r_actual - 1, N)][0];
                if (res >= dp[l][r][1]) {
                    dp[l][r][1] = res;
                }

                bef[l][r][1] = max(bef[l][r][1], 1);
            }
        }
    }

    int ans = 0;
    int starting = 0;
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            if (dp[i][j][0] > ans) {
                ans = dp[i][j][0];
                starting = i;
            }
            if (dp[i][j][1] > ans) {
                ans = dp[i][j][1];
                starting = j;
            }
        }
    }
    if (K == 0) {
        printf("%d\n%d\n", ans, starting + 1);
        return 0;
    }

    // Unite bef(before intersection) with dp(after intersection)
    for (int len = 0; len <= N; len++) {
        for (int l = 0; l < N; l++) {
            int r_actual = l + len - 1;
            int r = MOD(r_actual, N);

            bool g1 = stage[l][r];
            bool g2 = stage[r][l];

            for (int i_actual = l + 1; i_actual < r_actual; i_actual++) {
                int i = MOD(i_actual, N);

                int res = -INF;
                int s = -1;
                if (g2) {
                    res = bef[l][i][0];
                    s = r;
                }
                if (g1 && res < bef[i][r][1]) {
                    res = bef[i][r][1];
                    s = l;
                }
                res++;

                if (res < 0) {
                    continue;
                }

                int v = 0;
                for (int j = 0; j < adj_list[i].size(); j++) {
                    int n = adj_list[i][j];
                    if (n < N + l) {
                        v = max(v, 1 + dp[MOD(n, N)][MOD(l - 1 + N, N)][0]);
                    }
                    if (n > r_actual) {
                        v = max(v, 1 + dp[MOD(r + 1, N)][MOD(n, N)][1]);
                    }
                }

                if (ans < v + res) {
                    ans = v + res;
                    starting = s;
                }
            }
        }
    }

    printf("%d\n%d\n", ans, starting + 1);

    return 0;
}

Compilation message

race.cpp: In function 'int main()':
race.cpp:145:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  145 |                 for (int j = 0; j < adj_list[i].size(); j++) {
      |                                 ~~^~~~~~~~~~~~~~~~~~~~
race.cpp:33:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |     scanf("%d %d", &N, &K);
      |     ~~~~~^~~~~~~~~~~~~~~~~
race.cpp:39:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |         scanf("%d", &v);
      |         ~~~~~^~~~~~~~~~
race.cpp:46:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |             scanf("%d", &v);
      |             ~~~~~^~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Incorrect 1 ms 604 KB Output isn't correct
3 Incorrect 1 ms 604 KB Output isn't correct
4 Incorrect 1 ms 604 KB Output isn't correct
5 Correct 1 ms 2652 KB Output is correct
6 Incorrect 5 ms 2652 KB Output isn't correct
7 Correct 3 ms 2652 KB Output is correct
8 Incorrect 7 ms 2652 KB Output isn't correct
9 Correct 5 ms 2652 KB Output is correct
10 Correct 6 ms 3060 KB Output is correct
11 Correct 7 ms 2652 KB Output is correct
12 Incorrect 189 ms 3340 KB Output isn't correct
13 Incorrect 337 ms 3788 KB Output isn't correct
14 Correct 274 ms 4248 KB Output is correct
15 Execution timed out 3071 ms 4696 KB Time limit exceeded
16 Execution timed out 3034 ms 4956 KB Time limit exceeded
17 Execution timed out 3053 ms 4700 KB Time limit exceeded
18 Correct 529 ms 4700 KB Output is correct
19 Execution timed out 3021 ms 4952 KB Time limit exceeded
20 Execution timed out 3021 ms 4952 KB Time limit exceeded