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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. void solve() {
  5. 	int n, k;
  6. 	cin >> n >> k;
  7. 	vector<int> a(n + 1);
  8. 	for (int i = 1; i <= n; i++) {
  9. 		cin >> a[i];
  10. 	}
  11. 	if (n == k) {
  12. 		int ans = -1;
  13. 		for (int i = 2; i <= n; i += 2) {
  14. 			if (a[i] != i / 2) {
  15. 				ans = i / 2;
  16. 				break;
  17. 			}
  18. 		}
  19. 		if (ans == -1) {
  20. 			ans = n / 2 + 1;
  21. 		}
  22. 		cout << ans << endl;
  23. 	} else {
  24. 		int pos = -1;
  25. 		for (int i = 2; i <= n - k + 2; i++) {
  26. 			if (a[i] != 1) {
  27. 				pos = i;
  28. 				break;
  29. 			}
  30. 		}
  31. 		// cout << "pos: " << pos << endl;
  32. 		if (pos == -1) {
  33. 			int cur = 2;
  34. 			for (int i = n - k + 1; i <= n; i += 2) {
  35. 				if (a[i] != cur) {
  36. 					break;
  37. 				}
  38. 				cur++;
  39. 			}
  40. 			cout << cur << endl;
  41. 		} else {
  42. 			cout << 1 << endl;
  43. 		}
  44. 	}
  45.  
  46. }
  47.  
  48. int main() {
  49. 	int t;
  50. 	cin >> t;
  51. 	while (t--) solve();
  52. }
Success #stdin #stdout 0.01s 5288KB
comments (?)
stdin 
4
3 2
1 1 1
8 8
1 1 2 2 3 3 4 4
5 4
1 1 1 2 2
5 4
1 1 1000000000 2 2
stdout 
2
5
2
1
https://ideone.com/kc4EXA
language:
C++14 (gcc 8.3)
created:
38 days ago
visibility:
public

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