oj.uz

Submission #425427

# Submission time Handle Problem Language Result Execution time Memory
425427 2021-06-13T03:19:43 Z Kevin_Zhang_TW Sparklers (JOI17_sparklers) C++17
0 / 100
 3 ms 1228 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 = [&](ll d) {
				return 2 * S * (r-l+1) * T - (pos[r] - pos[l]) >= d;
			};
			
			if (dp[l][r]) {
				if (r < n) {
					ll d = pos[r+1] - pos[r];
					if (valid(d))
						dp[l][r+1] = true;
				}
				if (l > 1) {
					ll d = pos[l] - pos[l-1];
					if (valid(d))
						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];
 
	if (n <= 1) return puts("0"), 0;

	assert(n < MAX_N);
 
	ll L = 1, 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 'int32_t main()':
sparklers.cpp:73:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   73 |   M = L + R >> 1;
      |       ~~^~~

Subtask #1
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 1212 KB Output is correct
2 Correct 2 ms 1228 KB Output is correct
3 Correct 2 ms 1228 KB Output is correct
4 Correct 3 ms 1220 KB Output is correct
5 Correct 2 ms 1228 KB Output is correct
6 Correct 3 ms 1220 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 1220 KB Output is correct
18 Correct 3 ms 1228 KB Output is correct
19 Incorrect 1 ms 204 KB Output isn't correct
20 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 1212 KB Output is correct
2 Correct 2 ms 1228 KB Output is correct
3 Correct 2 ms 1228 KB Output is correct
4 Correct 3 ms 1220 KB Output is correct
5 Correct 2 ms 1228 KB Output is correct
6 Correct 3 ms 1220 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 1220 KB Output is correct
18 Correct 3 ms 1228 KB Output is correct
19 Incorrect 1 ms 204 KB Output isn't correct
20 Halted 0 ms 0 KB -

Subtask #3
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 1212 KB Output is correct
2 Correct 2 ms 1228 KB Output is correct
3 Correct 2 ms 1228 KB Output is correct
4 Correct 3 ms 1220 KB Output is correct
5 Correct 2 ms 1228 KB Output is correct
6 Correct 3 ms 1220 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 1220 KB Output is correct
18 Correct 3 ms 1228 KB Output is correct
19 Incorrect 1 ms 204 KB Output isn't correct
20 Halted 0 ms 0 KB -