Submission #69855

# Submission time Handle Problem Language Result Execution time Memory
69855 2018-08-21T16:53:23 Z Benq Sparklers (JOI17_sparklers) C++14
50 / 100
63 ms 2540 KB
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;

int N,K,T,mid;
vi X;
bool ok[1000][1000][2];

// k = 0: 
// X[i-1]+t*mid 
// currently at X[i]+t*mid 
// X[j]-t*mid 
// X[j+1]-t*mid

bool OK() {
    F0Rd(i,K+1) FOR(j,K,N) F0R(k,2) ok[i][j][k] = 0;
    ok[K][K][0] = ok[K][K][1] = 1;
    F0Rd(i,K+1) FOR(j,K,N) {
        ld dis = (ld)(j-i+1)*T*2*mid;
        ok[i][j][0] |= ok[i][j][1];
        ok[i][j][1] |= ok[i][j][0];
        if (i && dis >= X[j]-X[i-1]) ok[i-1][j][0] |= ok[i][j][0];
        if (j < N-1 && dis >= X[j+1]-X[i]) ok[i][j+1][1] |= ok[i][j][1];
    }
    return ok[0][N-1][0] || ok[0][N-1][1];
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N >> K >> T; X.resize(N); K--;
    F0R(i,N) cin >> X[i];
    int lo = 0, hi = 1000000000;
    while (lo < hi) {
        mid = (lo+hi)/2;
        if (OK()) hi = mid;
        else lo = mid+1;
    }
    cout << lo;
}

/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
* if you have no idea just guess the appropriate well-known algo instead of doing nothing :/
*/
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 3 ms 376 KB Output is correct
3 Correct 2 ms 392 KB Output is correct
4 Correct 2 ms 392 KB Output is correct
5 Correct 3 ms 392 KB Output is correct
6 Correct 2 ms 392 KB Output is correct
7 Correct 2 ms 468 KB Output is correct
8 Correct 2 ms 472 KB Output is correct
9 Correct 2 ms 572 KB Output is correct
10 Correct 3 ms 572 KB Output is correct
11 Correct 3 ms 572 KB Output is correct
12 Correct 2 ms 572 KB Output is correct
13 Correct 2 ms 572 KB Output is correct
14 Correct 2 ms 572 KB Output is correct
15 Correct 3 ms 572 KB Output is correct
16 Correct 2 ms 584 KB Output is correct
17 Correct 2 ms 584 KB Output is correct
18 Correct 2 ms 584 KB Output is correct
19 Correct 2 ms 584 KB Output is correct
20 Correct 3 ms 584 KB Output is correct
21 Correct 3 ms 612 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 3 ms 376 KB Output is correct
3 Correct 2 ms 392 KB Output is correct
4 Correct 2 ms 392 KB Output is correct
5 Correct 3 ms 392 KB Output is correct
6 Correct 2 ms 392 KB Output is correct
7 Correct 2 ms 468 KB Output is correct
8 Correct 2 ms 472 KB Output is correct
9 Correct 2 ms 572 KB Output is correct
10 Correct 3 ms 572 KB Output is correct
11 Correct 3 ms 572 KB Output is correct
12 Correct 2 ms 572 KB Output is correct
13 Correct 2 ms 572 KB Output is correct
14 Correct 2 ms 572 KB Output is correct
15 Correct 3 ms 572 KB Output is correct
16 Correct 2 ms 584 KB Output is correct
17 Correct 2 ms 584 KB Output is correct
18 Correct 2 ms 584 KB Output is correct
19 Correct 2 ms 584 KB Output is correct
20 Correct 3 ms 584 KB Output is correct
21 Correct 3 ms 612 KB Output is correct
22 Correct 31 ms 1136 KB Output is correct
23 Correct 15 ms 1136 KB Output is correct
24 Correct 9 ms 1136 KB Output is correct
25 Correct 6 ms 1136 KB Output is correct
26 Correct 24 ms 1136 KB Output is correct
27 Correct 29 ms 1136 KB Output is correct
28 Correct 63 ms 1776 KB Output is correct
29 Correct 46 ms 1776 KB Output is correct
30 Correct 34 ms 2156 KB Output is correct
31 Correct 35 ms 2156 KB Output is correct
32 Correct 56 ms 2156 KB Output is correct
33 Correct 59 ms 2156 KB Output is correct
34 Correct 27 ms 2284 KB Output is correct
35 Correct 52 ms 2284 KB Output is correct
36 Correct 19 ms 2284 KB Output is correct
37 Correct 18 ms 2284 KB Output is correct
38 Correct 44 ms 2284 KB Output is correct
39 Correct 16 ms 2540 KB Output is correct
40 Correct 45 ms 2540 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 3 ms 376 KB Output is correct
3 Correct 2 ms 392 KB Output is correct
4 Correct 2 ms 392 KB Output is correct
5 Correct 3 ms 392 KB Output is correct
6 Correct 2 ms 392 KB Output is correct
7 Correct 2 ms 468 KB Output is correct
8 Correct 2 ms 472 KB Output is correct
9 Correct 2 ms 572 KB Output is correct
10 Correct 3 ms 572 KB Output is correct
11 Correct 3 ms 572 KB Output is correct
12 Correct 2 ms 572 KB Output is correct
13 Correct 2 ms 572 KB Output is correct
14 Correct 2 ms 572 KB Output is correct
15 Correct 3 ms 572 KB Output is correct
16 Correct 2 ms 584 KB Output is correct
17 Correct 2 ms 584 KB Output is correct
18 Correct 2 ms 584 KB Output is correct
19 Correct 2 ms 584 KB Output is correct
20 Correct 3 ms 584 KB Output is correct
21 Correct 3 ms 612 KB Output is correct
22 Correct 31 ms 1136 KB Output is correct
23 Correct 15 ms 1136 KB Output is correct
24 Correct 9 ms 1136 KB Output is correct
25 Correct 6 ms 1136 KB Output is correct
26 Correct 24 ms 1136 KB Output is correct
27 Correct 29 ms 1136 KB Output is correct
28 Correct 63 ms 1776 KB Output is correct
29 Correct 46 ms 1776 KB Output is correct
30 Correct 34 ms 2156 KB Output is correct
31 Correct 35 ms 2156 KB Output is correct
32 Correct 56 ms 2156 KB Output is correct
33 Correct 59 ms 2156 KB Output is correct
34 Correct 27 ms 2284 KB Output is correct
35 Correct 52 ms 2284 KB Output is correct
36 Correct 19 ms 2284 KB Output is correct
37 Correct 18 ms 2284 KB Output is correct
38 Correct 44 ms 2284 KB Output is correct
39 Correct 16 ms 2540 KB Output is correct
40 Correct 45 ms 2540 KB Output is correct
41 Runtime error 20 ms 2540 KB Execution killed with signal 11 (could be triggered by violating memory limits)
42 Halted 0 ms 0 KB -