oj.uz

Submission #238598

# Submission time Handle Problem Language Result Execution time Memory
238598 2020-06-12T06:45:17 Z maomao90 Watching (JOI13_watching) C++14
100 / 100
 953 ms 16348 KB 
#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

#define INF 1000000005

int N, P, Q;
int A[2005];
int ans;

int memo[2005][2005];
int getMinQ(int i, int remP, int v) {
	if (i >= N) return 0;
	if (memo[i][remP] != -1) return memo[i][remP];
	int pNext = upper_bound(A + i, A + N, A[i] + v - 1) - A;
	int qNext = upper_bound(A + i, A + N, A[i] + 2 * v - 1) - A;
	// if (v == 9) printf("%d: %d, %d\n", i, pNext, qNext);
	if (remP == 0) return memo[i][remP] = getMinQ(qNext, remP, v) + 1;
	return memo[i][remP] = min(getMinQ(pNext, remP - 1, v), getMinQ(qNext, remP, v) + 1);
}

bool isPossible(int v) {
	memset(memo, -1, sizeof memo);
	// printf("%d: %d\n", v, getMinQ(0, P, v));
	return getMinQ(0, P, v) <= Q;
}

int main() {
	scanf("%d%d%d", &N, &P, &Q);
	for (int i = 0; i < N; i++)
		scanf("%d", &A[i]);
	if (P + Q >= N) {
		printf("1\n");
		return 0;
	}
	sort(A, A + N);
	int lo = 2, hi = INF, mid;
	while (lo <= hi) {
		mid = (lo + hi) / 2;
		if (isPossible(mid)) {
			hi = mid - 1;
			ans = mid;
		} else lo = mid + 1;
	}
	printf("%d\n", ans);
	return 0;
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:31:7: 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:33:8: 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 68 ms 16120 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 68 ms 16000 KB Output is correct
4 Correct 4 ms 256 KB Output is correct
5 Correct 4 ms 384 KB Output is correct
6 Correct 4 ms 256 KB Output is correct
7 Correct 67 ms 16000 KB Output is correct
8 Correct 68 ms 16000 KB Output is correct
9 Correct 68 ms 16000 KB Output is correct
10 Correct 69 ms 16120 KB Output is correct
11 Correct 69 ms 16000 KB Output is correct
12 Correct 69 ms 16000 KB Output is correct
13 Correct 69 ms 16120 KB Output is correct
14 Correct 69 ms 16000 KB Output is correct
15 Correct 67 ms 16000 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 69 ms 16000 KB Output is correct
2 Correct 5 ms 256 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 368 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 70 ms 16000 KB Output is correct
8 Correct 173 ms 16128 KB Output is correct
9 Correct 460 ms 16156 KB Output is correct
10 Correct 953 ms 16348 KB Output is correct
11 Correct 172 ms 16224 KB Output is correct
12 Correct 816 ms 16212 KB Output is correct
13 Correct 70 ms 16000 KB Output is correct
14 Correct 69 ms 16000 KB Output is correct
15 Correct 70 ms 16104 KB Output is correct