oj.uz

Submission #103654

# Submission time Handle Problem Language Result Execution time Memory
103654 2019-04-01T19:20:53 Z igba Watching (JOI13_watching) C++17
50 / 100
 161 ms 16476 KB 
#include <bits/stdc++.h>

using namespace std;
const int MAXN = 2020, INF = 0x3f3f3f3f;
int n, p, q, a[MAXN], precalc[MAXN][2], dp[MAXN][MAXN];

bool ok(int w)
{
	for(int i = 1, j = 1; i <= n; ++i, j = i)
	{
		while(a[j] - a[i] < w && j <= n)
			j++;
		precalc[i][0] = j;
		while(a[j] - a[i] < 2 * w && j <= n)
			j++;
		precalc[i][1] = j;
	}
	precalc[n + 1][0] = precalc[n + 1][1] = n + 1;
	memset(dp, 0, sizeof dp);
	dp[1][0] = precalc[1][0], dp[0][1] = precalc[1][1];
	for(int i = 1; i <= p; ++i)
		for(int j = 1; j <= q; ++j)
			dp[i][j] = max(precalc[dp[i - 1][j]][0], precalc[dp[i][j - 1]][1]);
	return dp[p][q] > n;
}

int main()
{
	scanf("%d %d %d", &n, &p, &q);
	for(int i = 1; i <= n; ++i)
		scanf("%d", &a[i]);
	sort(a + 1, a + n + 1);
	if(p + q >= n)
		printf("1\n"), exit(0);
	int beg = 1, end = 1e9, mid;
	while(beg < end)
	{
		mid = (beg + end) >> 1;
		if(ok(mid))
			end = mid;
		else
			beg = mid + 1;
	}
	printf("%d\n", end);
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:29:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d", &n, &p, &q);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
watching.cpp:31:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i]);
   ~~~~~^~~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 53 ms 16256 KB Output is correct
2 Correct 2 ms 256 KB Output is correct
3 Correct 53 ms 16376 KB Output is correct
4 Correct 2 ms 256 KB Output is correct
5 Correct 2 ms 256 KB Output is correct
6 Correct 2 ms 384 KB Output is correct
7 Correct 70 ms 16328 KB Output is correct
8 Correct 47 ms 16256 KB Output is correct
9 Correct 58 ms 16376 KB Output is correct
10 Correct 66 ms 16336 KB Output is correct
11 Correct 55 ms 16256 KB Output is correct
12 Correct 52 ms 16288 KB Output is correct
13 Correct 55 ms 16256 KB Output is correct
14 Correct 80 ms 16376 KB Output is correct
15 Correct 66 ms 16256 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 161 ms 16376 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 3 ms 384 KB Output is correct
6 Correct 3 ms 384 KB Output is correct
7 Correct 127 ms 16396 KB Output is correct
8 Correct 98 ms 16384 KB Output is correct
9 Incorrect 101 ms 16476 KB Output isn't correct
10 Halted 0 ms 0 KB -