Submission #127053

# Submission time Handle Problem Language Result Execution time Memory
127053 2019-07-08T20:39:20 Z eriksuenderhauf Sailing Race (CEOI12_race) C++11
95 / 100
2752 ms 7672 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 > 400) 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 12 ms 6392 KB Output is correct
5 Correct 6 ms 4344 KB Output is correct
6 Correct 20 ms 6392 KB Output is correct
7 Correct 8 ms 4476 KB Output is correct
8 Correct 29 ms 6520 KB Output is correct
9 Correct 9 ms 4472 KB Output is correct
10 Correct 16 ms 4708 KB Output is correct
11 Correct 11 ms 4476 KB Output is correct
12 Correct 234 ms 6784 KB Output is correct
13 Correct 659 ms 7032 KB Output is correct
14 Correct 61 ms 5240 KB Output is correct
15 Incorrect 2494 ms 7508 KB Output isn't correct
16 Correct 2752 ms 7520 KB Output is correct
17 Correct 2584 ms 7544 KB Output is correct
18 Correct 75 ms 5496 KB Output is correct
19 Correct 2707 ms 7672 KB Output is correct
20 Correct 2731 ms 7544 KB Output is correct