oj.uz

Submission #51451

# Submission time Handle Problem Language Result Execution time Memory
51451 2018-06-18T03:03:01 Z Vinhspm Watching (JOI13_watching) C++14
100 / 100
 109 ms 8868 KB 
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ii pair<int, int>
#define fi first
#define se second
#define pb push_back
const int N = 2009;
const int oo = 1e9;
const int mod = 1e9 + 7;
int n, P, Q;
int a[N], dp[N][N], calc[N][2];
bool check(int x)	{
	// base
	for(int i = 0; i <= n; ++i)	{
		calc[i][0] = upper_bound(a + 1, a + n + 1, a[i] + x - 1) - a - 1;
		calc[i][1] = upper_bound(a + 1, a + n + 1, a[i] + 2*x - 1) - a - 1;
	}
	for(int i = 0; i <= P; ++ i)
		for(int j = 0; j <= Q; ++j)
			dp[i][j] = -1;
	dp[0][0] = 0;
	for(int i = 0; i <= P; ++i)
		for(int j = 0; j <= Q; ++j){
				if(i > 0)	{
					int cur = dp[i - 1][j] + 1;
					dp[i][j] = max(dp[i][j], calc[cur][0]);
				}
				if(j > 0)	{
					int cur = dp[i][j - 1] + 1;
					dp[i][j] = max(dp[i][j], calc[cur][1]);
				}
				if(dp[i][j] == n) return true;
			}
	return false;
}
signed main()
{
	//freopen("test.txt", "r", stdin);
	//ios_base::sync_with_stdio(false);
	//cin.tie(0); cout.tie(0);
	scanf("%d%d%d", &n, &P, &Q);
	for(int i = 1; i <= n; ++i) scanf("%d", &a[i]);
	sort(a + 1, a + n + 1); 
	a[0] = 0;
	if(P + Q >= n) {
		printf("1");
		return 0;
	}
	//cout << check(3) << '\n'; return 0;
	int l = 1, r = 1e9;
	while(r > l + 1)	{
		int mid = (l + r)/ 2;
		if(check(mid)) r = mid;
		else l = mid;
	}
	for(int i = l; i <= r; ++i)
		if(check(i))	{
			printf("%d", i); 
			return 0;
		}
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:42:7: 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:43:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i = 1; i <= n; ++i) scanf("%d", &a[i]);
                              ~~~~~^~~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 3 ms 356 KB Output is correct
3 Correct 3 ms 484 KB Output is correct
4 Correct 2 ms 484 KB Output is correct
5 Correct 2 ms 508 KB Output is correct
6 Correct 2 ms 508 KB Output is correct
7 Correct 3 ms 524 KB Output is correct
8 Correct 2 ms 556 KB Output is correct
9 Correct 3 ms 680 KB Output is correct
10 Correct 3 ms 752 KB Output is correct
11 Correct 3 ms 868 KB Output is correct
12 Correct 2 ms 868 KB Output is correct
13 Correct 3 ms 868 KB Output is correct
14 Correct 3 ms 868 KB Output is correct
15 Correct 3 ms 868 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 868 KB Output is correct
2 Correct 2 ms 868 KB Output is correct
3 Correct 3 ms 868 KB Output is correct
4 Correct 2 ms 868 KB Output is correct
5 Correct 3 ms 868 KB Output is correct
6 Correct 3 ms 868 KB Output is correct
7 Correct 7 ms 868 KB Output is correct
8 Correct 20 ms 1380 KB Output is correct
9 Correct 30 ms 3940 KB Output is correct
10 Correct 35 ms 8868 KB Output is correct
11 Correct 20 ms 8868 KB Output is correct
12 Correct 109 ms 8868 KB Output is correct
13 Correct 9 ms 8868 KB Output is correct
14 Correct 9 ms 8868 KB Output is correct
15 Correct 9 ms 8868 KB Output is correct