Submission #127057

# Submission time Handle Problem Language Result Execution time Memory
127057 2019-07-08T20:40:56 Z eriksuenderhauf Sailing Race (CEOI12_race) C++11
85 / 100
3000 ms 7548 KB
//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
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];
bool adj[MAXN][MAXN];
int nex[MAXN][MAXN];
int n;
 
inline bool between(int l, int r, int x) {
    if (l > r)
        return l < x || x < r;
    return l < x && x < r;
}
 
int solve(int l, int r, int k) {// path ends at r, interval at l
    if (dp[l][r][k] != -1) return dp[l][r][k];
    int &ret = dp[l][r][k];
    ret = 0;
    int lo = k ? r : l;
    int hi = l ^ r ^ lo;
    for (int i=1; i <= nex[r][0]; i++)
        if (between(lo, hi, nex[r][i]))
            ret = max(ret, max(solve(r, nex[r][i], k^1),  solve(l, nex[r][i], k)) + 1);
    return ret;
}
 
int f2(int l, int r, int k) {
    if (l == r) return 0;
    if (dp2[l][r][k] != -1) return dp2[l][r][k];
    int ret = adj[l][r] ? 0 : -INF;
    int lo = k ? r : l;
    int hi = l ^ r ^ lo;
    for (int i=1; i <= nex[l][0]; i++)
        if (between(lo, hi, nex[l][i]))
            ret = max(ret, f2(nex[l][i], r, k));
    return dp2[l][r][k] = ret + 1;
}
 
int b[MAXN];

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++) {
        b[i] = i;
        int x;
        while (1) {
            scanf("%d", &x);
            if (x == 0)
                break;
            adj[i][x] = 1;
            nex[i][++nex[i][0]] = x;
        }
    }
    for (int i = 1; i <= n; i++)
        for (int j=1; j <= nex[i][0]; j++)
            ans[i] = max(ans[i], max(solve(i, nex[i][j], 0), solve(i, nex[i][j], 1)) + 1);
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    shuffle(b+1,b+n+1, rng);
    if (k == 1) for (int ii = 1; ii <= n; ii++) {
        int i = b[ii];
        memset(mx, 0, sizeof mx);
        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) {
                mx[x][y][0] = mx[x][(y+n-2)%n + 1][0];
                if (adj[i][(y+n-2)%n + 1])
                    mx[x][y][0] = max(mx[x][y][0], dp[x][(y+n-2)%n + 1][0] + 1);
            }
        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) {
                mx[y][x][1] = mx[y%n+1][x][1];
                if (adj[i][y%n+1])
                    mx[y][x][1] = max(mx[y][x][1], dp[x][y%n+1][1] + 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);
            }
        if (ans[i] == n || ii > 450) break;
    }
    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:48:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &k);
     ~~~~~^~~~~~~~~~~~~~~~~
race.cpp:53:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d", &x);
             ~~~~~^~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 5 ms 4344 KB Output is correct
2 Correct 9 ms 6264 KB Output is correct
3 Correct 10 ms 6392 KB Output is correct
4 Correct 13 ms 6392 KB Output is correct
5 Correct 6 ms 4472 KB Output is correct
6 Correct 19 ms 6392 KB Output is correct
7 Correct 8 ms 4472 KB Output is correct
8 Correct 28 ms 6520 KB Output is correct
9 Correct 9 ms 4472 KB Output is correct
10 Correct 16 ms 4600 KB Output is correct
11 Correct 11 ms 4600 KB Output is correct
12 Correct 234 ms 6904 KB Output is correct
13 Correct 646 ms 7064 KB Output is correct
14 Correct 60 ms 5240 KB Output is correct
15 Incorrect 2832 ms 7548 KB Output isn't correct
16 Correct 2930 ms 7468 KB Output is correct
17 Correct 2791 ms 7416 KB Output is correct
18 Correct 73 ms 5496 KB Output is correct
19 Execution timed out 3047 ms 7548 KB Time limit exceeded
20 Execution timed out 3048 ms 7544 KB Time limit exceeded