oj.uz

Submission #425429

# Submission time Handle Problem Language Result Execution time Memory
425429 2021-06-13T03:27:12 Z Kevin_Zhang_TW Sparklers (JOI17_sparklers) C++17
50 / 100
 42 ms 1324 KB 
#include<bits/stdc++.h>
#define pb emplace_back
#define AI(i) begin(i), end(i)
using namespace std;
using ll = long long;
template<class T> bool chmin(T &a, T b) { return b < a && (a = b, true); }
template<class T> bool chmax(T &a, T b) { return a < b && (a = b, true); }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() {cerr << endl;}
template<class T, class ...U> void kout (T v, U ...e) { cerr << v << ' ', kout(e...); }
template<class T> void debug(T L, T R) { while (L != R) cerr << *L << " \n"[next(L)==R], ++L; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
// What I should check
// 1. overflow
// 2. corner cases
// Enjoy the problem instead of hurrying to AC
// Good luck !
const int MAX_N = 1010;
 
const ll inf = 1ll << 55;
 
int n, k, T;
int pos[MAX_N];
 
bool dp[MAX_N][MAX_N];
ll a[MAX_N];

bool valid(ll S) {
	memset(dp, 0, sizeof(dp));

	dp[k][k] = true;
	for (int l = k;l >= 1;--l)
		for (int r = k;r <= n;++r) {

			auto valid = [&](int l, int r) {
				return 2 * S * (r-l) * T >= (pos[r] - pos[l]);
			};
			
			if (dp[l][r]) {
				if (r < n) {
					ll d = pos[r+1] - pos[r];
					if (valid(l, r+1))
						dp[l][r+1] = true;
				}
				if (l > 1) {
					ll d = pos[l] - pos[l-1];
					if (valid(l-1, r))
						dp[l-1][r] = true;
				}
			}
		}

	return dp[1][n];
}
 
int32_t main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	cin >> n >> k >> T;
	for (int i = 1;i <= n;++i)
		cin >> pos[i];

	//assert(n < MAX_N);
 
	ll L = 0, R = 2 * pos[n], M;
 
	while (L < R) {
		M = L + R >> 1;
		if (valid(M))
			R = M;
		else L = M + 1;
	}
 
	cout << L << '\n';
	
}

Compilation message

sparklers.cpp: In function 'bool valid(ll)':
sparklers.cpp:45:9: warning: unused variable 'd' [-Wunused-variable]
   45 |      ll d = pos[r+1] - pos[r];
      |         ^
sparklers.cpp:50:9: warning: unused variable 'd' [-Wunused-variable]
   50 |      ll d = pos[l] - pos[l-1];
      |         ^
sparklers.cpp: In function 'int32_t main()':
sparklers.cpp:71:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   71 |   M = L + R >> 1;
      |       ~~^~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 1228 KB Output is correct
2 Correct 2 ms 1228 KB Output is correct
3 Correct 2 ms 1228 KB Output is correct
4 Correct 2 ms 1228 KB Output is correct
5 Correct 2 ms 1228 KB Output is correct
6 Correct 2 ms 1228 KB Output is correct
7 Correct 2 ms 1228 KB Output is correct
8 Correct 2 ms 1228 KB Output is correct
9 Correct 2 ms 1228 KB Output is correct
10 Correct 2 ms 1228 KB Output is correct
11 Correct 2 ms 1228 KB Output is correct
12 Correct 2 ms 1228 KB Output is correct
13 Correct 2 ms 1228 KB Output is correct
14 Correct 2 ms 1228 KB Output is correct
15 Correct 2 ms 1228 KB Output is correct
16 Correct 2 ms 1228 KB Output is correct
17 Correct 2 ms 1228 KB Output is correct
18 Correct 2 ms 1228 KB Output is correct
19 Correct 0 ms 204 KB Output is correct
20 Correct 2 ms 1228 KB Output is correct
21 Correct 0 ms 204 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 1228 KB Output is correct
2 Correct 2 ms 1228 KB Output is correct
3 Correct 2 ms 1228 KB Output is correct
4 Correct 2 ms 1228 KB Output is correct
5 Correct 2 ms 1228 KB Output is correct
6 Correct 2 ms 1228 KB Output is correct
7 Correct 2 ms 1228 KB Output is correct
8 Correct 2 ms 1228 KB Output is correct
9 Correct 2 ms 1228 KB Output is correct
10 Correct 2 ms 1228 KB Output is correct
11 Correct 2 ms 1228 KB Output is correct
12 Correct 2 ms 1228 KB Output is correct
13 Correct 2 ms 1228 KB Output is correct
14 Correct 2 ms 1228 KB Output is correct
15 Correct 2 ms 1228 KB Output is correct
16 Correct 2 ms 1228 KB Output is correct
17 Correct 2 ms 1228 KB Output is correct
18 Correct 2 ms 1228 KB Output is correct
19 Correct 0 ms 204 KB Output is correct
20 Correct 2 ms 1228 KB Output is correct
21 Correct 0 ms 204 KB Output is correct
22 Correct 13 ms 1320 KB Output is correct
23 Correct 9 ms 1324 KB Output is correct
24 Correct 5 ms 1228 KB Output is correct
25 Correct 3 ms 1228 KB Output is correct
26 Correct 13 ms 1320 KB Output is correct
27 Correct 14 ms 1320 KB Output is correct
28 Correct 28 ms 1228 KB Output is correct
29 Correct 42 ms 1228 KB Output is correct
30 Correct 17 ms 1228 KB Output is correct
31 Correct 17 ms 1228 KB Output is correct
32 Correct 21 ms 1320 KB Output is correct
33 Correct 23 ms 1228 KB Output is correct
34 Correct 12 ms 1324 KB Output is correct
35 Correct 26 ms 1316 KB Output is correct
36 Correct 9 ms 1320 KB Output is correct
37 Correct 10 ms 1228 KB Output is correct
38 Correct 20 ms 1228 KB Output is correct
39 Correct 7 ms 1228 KB Output is correct
40 Correct 1 ms 204 KB Output is correct

Subtask #3
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 1228 KB Output is correct
2 Correct 2 ms 1228 KB Output is correct
3 Correct 2 ms 1228 KB Output is correct
4 Correct 2 ms 1228 KB Output is correct
5 Correct 2 ms 1228 KB Output is correct
6 Correct 2 ms 1228 KB Output is correct
7 Correct 2 ms 1228 KB Output is correct
8 Correct 2 ms 1228 KB Output is correct
9 Correct 2 ms 1228 KB Output is correct
10 Correct 2 ms 1228 KB Output is correct
11 Correct 2 ms 1228 KB Output is correct
12 Correct 2 ms 1228 KB Output is correct
13 Correct 2 ms 1228 KB Output is correct
14 Correct 2 ms 1228 KB Output is correct
15 Correct 2 ms 1228 KB Output is correct
16 Correct 2 ms 1228 KB Output is correct
17 Correct 2 ms 1228 KB Output is correct
18 Correct 2 ms 1228 KB Output is correct
19 Correct 0 ms 204 KB Output is correct
20 Correct 2 ms 1228 KB Output is correct
21 Correct 0 ms 204 KB Output is correct
22 Correct 13 ms 1320 KB Output is correct
23 Correct 9 ms 1324 KB Output is correct
24 Correct 5 ms 1228 KB Output is correct
25 Correct 3 ms 1228 KB Output is correct
26 Correct 13 ms 1320 KB Output is correct
27 Correct 14 ms 1320 KB Output is correct
28 Correct 28 ms 1228 KB Output is correct
29 Correct 42 ms 1228 KB Output is correct
30 Correct 17 ms 1228 KB Output is correct
31 Correct 17 ms 1228 KB Output is correct
32 Correct 21 ms 1320 KB Output is correct
33 Correct 23 ms 1228 KB Output is correct
34 Correct 12 ms 1324 KB Output is correct
35 Correct 26 ms 1316 KB Output is correct
36 Correct 9 ms 1320 KB Output is correct
37 Correct 10 ms 1228 KB Output is correct
38 Correct 20 ms 1228 KB Output is correct
39 Correct 7 ms 1228 KB Output is correct
40 Correct 1 ms 204 KB Output is correct
41 Runtime error 1 ms 460 KB Execution killed with signal 11
42 Halted 0 ms 0 KB -