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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. void solve() {
  5. 	int n, m;
  6. 	cin >> n >> m;
  7. 	vector<int> a(n), b(m);
  8. 	for (int i = 0; i < n; i++) cin >> a[i];
  9. 	cin >> b[0];
  10. 	bool strict_increasing = true;
  11. 	for (int i = 0; i < n - 1; i++) {
  12. 		if (a[i] > a[i + 1]) {
  13. 			strict_increasing = false;
  14. 			break;
  15. 		}
  16. 	}
  17. 	if (strict_increasing) {
  18. 		cout << "YES" << endl;
  19. 		return;
  20. 	}
  21. 	bool strict_decreasing = true;
  22. 	for (int i = 0; i < n - 1; i++) {
  23. 		if (a[i] < a[i + 1]) {
  24. 			strict_decreasing = false;
  25. 			break;
  26. 		}
  27. 	}
  28. 	if (strict_decreasing) {
  29. 		cout << "YES" << endl;
  30. 		return;
  31. 	}
  32.  
  33. 	a[0] = min(a[0], b[0] - a[0]);
  34.  
  35. 	for (int i = 1; i < n; i++) {
  36.  
  37. 		if (a[i] < a[i - 1]) {
  38. 			if (b[0] - a[i] < a[i - 1]) {
  39. 				cout << "NO" << endl;
  40. 				return;
  41. 			} else {
  42. 				a[i] = b[0] - a[i];
  43. 			}
  44. 		} else {
  45. 			if (b[0] - a[i] >= a[i - 1]) {
  46. 				a[i] = b[0] - a[i];
  47. 			}
  48. 		}
  49. 	}
  50.  
  51. 	cout << "YES" << endl;
  52. }
  53.  
  54. int main() {
  55. 	int t;
  56. 	cin >> t;
  57. 	while (t--) solve();
  58. }
Success #stdin #stdout 0.01s 5292KB
comments (?)
stdin
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5
1 1
5
9
3 1
1 4 3
3
4 1
1 4 2 5
6
4 1
5 4 10 5
4
3 1
9 8 7
8
stdout
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YES
NO
YES
NO
YES
https://ideone.com/wBxEAB
language:
C++14 (gcc 8.3)
created:
12 days ago
visibility:
public

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