Submission #127021

# Submission time Handle Problem Language Result Execution time Memory
127021 2019-07-08T19:52:46 Z eriksuenderhauf Sailing Race (CEOI12_race) C++11
75 / 100
3000 ms 7532 KB
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define enl printf("\n")
#define ni(n) scanf("%d", &(n))
#define pri(n) printf("%d\n", (n))
#define pii pair<int, int>
#define pll pair<long long, long long>
#define vii vector<pii>
#define vi vector<int>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
using namespace std;
typedef long long ll;
const int MAXN = 5e2 + 2;
const int INF = 1e9 + 7;
int ans[MAXN], mx[MAXN][MAXN][2];
int dp[MAXN][MAXN][2], dp2[MAXN][MAXN][2];
int adj[MAXN][MAXN];
vi nex[MAXN];
int n;

int solve(int l, int r, int k) {// path ends at r, interval at l
    if (~dp[l][r][k]) return dp[l][r][k];
    int &ret = dp[l][r][k];
    ret = 0;
    if (k) { // ccw
        for (int i = (r%n) + 1; i != l; i = (i%n) + 1)
            if (adj[r][i])
                ret = max(ret, max(solve(r, i, 0),  solve(l, i, 1)) + 1);
    } else { // cw
        for (int i = (l%n) + 1; i != r; i = (i%n) + 1)
            if (adj[r][i])
                ret = max(ret, max(solve(r, i, 1), solve(l, i, 0)) + 1);
    }
    return ret;
}

int f2(int l, int r, int k) {
    if (l == r)
        return 0;
    if (~dp2[l][r][k])
        return dp2[l][r][k];
    int ret = adj[l][r] ? 0 : -INF;
    if (k) {
        for (int i = r%n+1; i != l; i = (i%n) + 1)
            if (adj[l][i])
                ret = max(ret, f2(i, r, 1));
    } else {
        for (int i = l%n+1; i != r; i = (i%n) + 1)
            if (adj[l][i])
                ret = max(ret, f2(i, r, 0));
    }
    return dp2[l][r][k] = ret + 1;
}

int main() {
    memset(dp, -1, sizeof dp);
    memset(dp2, -1, sizeof dp2);
    int k;
    scanf("%d %d", &n, &k);
    for (int i = 1; i <= n; i++) {
        while (1) {
            int x; ni(x);
            if (x == 0)
                break;
            adj[i][x] = 1;
            nex[i].pb(x);
        }
    }
    for (int i = 1; i <= n; i++)
        for (int j: nex[i])
            ans[i] = max(ans[i], max(solve(i, j, 0), solve(i, j, 1)) + 1);
    if (k == 1) for (int i = 1; i <= n; i++) {
        for (int x = (i%n) + 1; x != i; x = (x%n) + 1)
            for (int y = (x+1)%n + 1; y != i; y = (y%n) + 1)
                if (adj[i][(y+n-2)%n + 1])
                    mx[x][y][0] = max(solve(x, (y+n-2)%n + 1, 0) + 1, mx[x][(y+n-2)%n + 1][0]);
                else
                    mx[x][y][0] = max(0, mx[x][(y+n-2)%n + 1][0]);
        for (int x = (i+n-2)%n+1; x != i; x = (x-2+n)%n+1)
            for (int y = (x+2*n-3)%n+1; y != i; y = (y-2+n)%n+1)
                if (adj[i][y%n+1])
                    mx[y][x][1] = max(solve(x, y%n+1, 1) + 1, mx[y%n+1][x][1]);
                else
                    mx[y][x][1] = max(0, mx[y%n+1][x][1]);

        for (int l = i%n+1; l != (i+2*n-3)%n+1; l = (l%n) + 1)
            for (int j = (l+1)%n+1; j != i; j = (j%n) + 1) {
                if (adj[l][j])
                    ans[l] = max(ans[l], max(f2(j, i, 0) + mx[l][j][0], f2(j, i, 0) + mx[l][j][1]) + 1);
                if (adj[j][l])
                    ans[j] = max(ans[j], max(f2(l, i, 1) + mx[l][j][0], f2(l, i, 1) + mx[l][j][1]) + 1);
            }
    }
    int ind = 0;
    for (int i = 1; i <= n; i++)
        if (ans[ind] < ans[i])
            ind = i;
    printf("%d\n%d\n", ans[ind], ind);
    return 0;
}

Compilation message

race.cpp: In function 'int main()':
race.cpp:62:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &k);
     ~~~~~^~~~~~~~~~~~~~~~~
race.cpp:4:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 #define ni(n) scanf("%d", &(n))
               ~~~~~^~~~~~~~~~~~
race.cpp:65:20: note: in expansion of macro 'ni'
             int x; ni(x);
                    ^~
# Verdict Execution time Memory Grader output
1 Correct 5 ms 4344 KB Output is correct
2 Correct 6 ms 4344 KB Output is correct
3 Correct 6 ms 4472 KB Output is correct
4 Correct 8 ms 4472 KB Output is correct
5 Correct 7 ms 4344 KB Output is correct
6 Correct 16 ms 4604 KB Output is correct
7 Correct 11 ms 4500 KB Output is correct
8 Correct 29 ms 4732 KB Output is correct
9 Correct 16 ms 4472 KB Output is correct
10 Correct 18 ms 4600 KB Output is correct
11 Correct 20 ms 4472 KB Output is correct
12 Correct 391 ms 5468 KB Output is correct
13 Correct 1180 ms 6264 KB Output is correct
14 Correct 589 ms 5112 KB Output is correct
15 Execution timed out 3037 ms 7516 KB Time limit exceeded
16 Execution timed out 3067 ms 7484 KB Time limit exceeded
17 Execution timed out 3059 ms 7420 KB Time limit exceeded
18 Correct 1014 ms 5412 KB Output is correct
19 Execution timed out 3058 ms 7532 KB Time limit exceeded
20 Execution timed out 3055 ms 7516 KB Time limit exceeded