oj.uz

Submission #802583

# Submission time Handle Problem Language Result Execution time Memory
802583 2023-08-02T12:49:32 Z KN200711 Watching (JOI13_watching) C++14
100 / 100
 292 ms 15976 KB 
# include <bits/stdc++.h>
# define ll long long
using namespace std;

int N, P, Q;
vector<int> arr;

int mn[2001][2001];
int edge[2][2001];

bool cek(int a) {
	// set edge nya dulu
	for(int i=0;i<N;i++) {
		int T = arr[i] + a - 1;
		edge[0][i] = upper_bound(arr.begin(), arr.end(), T) - arr.begin();
		T += a;
		edge[1][i] = upper_bound(arr.begin(), arr.end(), T) - arr.begin();
		
	//	if(a == 4) cout<<i<<" "<<edge[0][i]<<" "<<edge[1][i]<<endl;
	}
	
	for(int i=0;i<=N;i++) {
		for(int k=0;k<=P;k++) mn[i][k] = 1e9;
	}
	mn[0][0] = 0;
	for(int i=0;i<N;i++) {
		for(int k=0;k+1<=P;k++) {
			mn[edge[0][i]][k + 1] = min(mn[edge[0][i]][k+1], mn[i][k]);
		}
		for(int k=0;k<=P;k++) {
			mn[edge[1][i]][k] = min(mn[edge[1][i]][k], mn[i][k] + 1);
		}
	}
	for(int c=0;c<=P;c++) {
		if(mn[N][c] <= Q) return 1;
	}
	return 0;
}

int main() {
	scanf("%d %d %d", &N, &P, &Q);
	arr.resize(N);
	for(int i=0;i<N;i++) scanf("%d", &arr[i]);
	sort(arr.begin(), arr.end());
	
	if(P + Q >= N) {
		printf("1\n");
		return 0;
	}
	
	for(int i=0;i<=N;i++) {
		for(int k=0;k<=P;k++) mn[i][k] = 1e9;
	}
//	cout<<cek(4)<<endl;
	int l = 1, r = 1e9, ans = -1;
	while(l <= r) {
		int mid = (l + r) / 2;
		if(cek(mid)) {
			ans = mid;
			r = mid - 1;
		} else l = mid + 1;
	}
	printf("%d\n", ans);
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:41:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |  scanf("%d %d %d", &N, &P, &Q);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
watching.cpp:43:28: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |  for(int i=0;i<N;i++) scanf("%d", &arr[i]);
      |                       ~~~~~^~~~~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 724 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 312 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 0 ms 312 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 724 KB Output is correct
8 Correct 1 ms 724 KB Output is correct
9 Correct 1 ms 724 KB Output is correct
10 Correct 1 ms 724 KB Output is correct
11 Correct 1 ms 724 KB Output is correct
12 Correct 1 ms 724 KB Output is correct
13 Correct 1 ms 724 KB Output is correct
14 Correct 1 ms 724 KB Output is correct
15 Correct 1 ms 724 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 8276 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 368 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 8 ms 8404 KB Output is correct
8 Correct 26 ms 9300 KB Output is correct
9 Correct 109 ms 14164 KB Output is correct
10 Correct 292 ms 15976 KB Output is correct
11 Correct 21 ms 9048 KB Output is correct
12 Correct 165 ms 15972 KB Output is correct
13 Correct 10 ms 8412 KB Output is correct
14 Correct 11 ms 8520 KB Output is correct
15 Correct 11 ms 8404 KB Output is correct