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  1. #include <iostream>
  2. using namespace std;
  3.  
  4. /* построение дерева */
  5. void build (int tree[], int arr[], int v, int left, int right) {   
  6. 	if (left == right) {
  7. 		tree[v] = arr[left];
  8. 	}
  9. 	else {
  10. 		int middle = (left + right) / 2;
  11. 		build (tree, arr, v*2, left, middle);
  12. 		build (tree, arr, v*2+1, middle+1, right);
  13. 		tree[v] = tree[v*2] + tree[v*2+1];
  14. 	}
  15. }
  16.  
  17. /* запрос суммы */
  18. int sum (int tree[], int v, int left, int right, int from, int to) { 
  19. 	if (from > to) { 
  20. 		return 0;
  21. 	}
  22. 	if (from == left && to == right) {
  23. 		return tree[v];
  24. 	}
  25. 	int middle = (left + right) / 2;
  26. 	return sum (tree, v*2, left, middle, from, min(to,middle))
  27. 		+ sum (tree, v*2+1, middle+1, right, max(from,middle+1), to);
  28. }
  29.  
  30. 	/* операция присваивания*/
  31. void update (int tree[], int v, int left, int right, int index, int new_val) { 
  32. 	if (left == right) {
  33. 		tree[v] = new_val;
  34. 	}
  35. 	else {
  36. 		int middle = (left + right) / 2;
  37. 		if (index <= middle) {
  38. 			update (tree, v*2, left, middle, index, new_val);
  39. 		}
  40. 		else {
  41. 			update (tree, v*2+1, middle+1, right, index, new_val);
  42. 		}
  43. 		tree[v] = tree[v*2] + tree[v*2+1];
  44. 	}
  45. }
  46. int main() {
  47. 	int n, q, i, d, from, to;
  48. 	char query;
  49. 	cin >> n >> q;
  50. 	int size = 2*n; /* максимальный размер дерева*/
  51.     int arr[n+1], tree[size];
  52.     for(int i = 0; i < n; i++){
  53.     	cin >> arr[i];
  54.     }
  55.     build(tree, arr, 1, 0, n-1); /* передаем функции построения массив для записи
  56. 								 дерева, исходный массив, корень и границы отрезка, 
  57.                                 принадлежащего корню*/
  58.     for (q; q>0; q--) {
  59.     	cin >> query;
  60.     	if(query == '=') {
  61.     		cin >> i >> d;
  62.     		update(tree, 1, 0, n-1, i-1, d); 
  63.     	}
  64.     	else if (query == '?') {
  65.     		cin >> from >> to;
  66.     		cout << sum(tree, 1, 0, n-1, from-1, to-1) << endl;
  67.     	}
  68.  
  69.     }
  70.  
  71. 	return 0;
  72. }
Success #stdin #stdout 0s 3464KB
comments (?)
stdin
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5 6
1 2 3 4 5
? 1 5
= 1 0
? 1 5
= 2 7
? 1 5
? 1 3
stdout
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15
14
19
10
https://ideone.com/yWY8yc
2941
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
secret

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