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线段树的表示如下，图中树的值表示区间值得和,线段树的表示和堆的表示方法相同。

代码

#include 
   
    #define MAX_LEN 1000void build_tree(int arr[], int tree[], int node, int start, int end) {	if (start == end) {		tree[node] = arr[start];		return;	}	int mid = start + (end - start) / 2;	int left_node = node * 2 + 1;	int right_node = node * 2 + 2;	build_tree(arr, tree, left_node, start, mid);	build_tree(arr, tree, right_node, mid + 1, end);	tree[node] = tree[left_node] + tree[right_node];}void update_tree(int arr[], int tree[], int node, int start, int end, int idx, int val) {	if (start == end) {		arr[idx] = val;		tree[node] = val;		return;	}	int mid = start + (end - start) / 2;	int left_node = node * 2 + 1;	int right_node = node * 2 + 2;	if (idx >= start && idx <= mid)		update_tree(arr, tree, left_node, start, mid, idx, val);	else		update_tree(arr, tree, right_node, mid + 1, end, idx, val);	tree[node] = tree[left_node] + tree[right_node];}int query_tree(int arr[], int tree[], int node, int start, int end, int L, int R) {	if (R
    
      end)		return 0;	else if (L <= start && end <= R)		return tree[node];	else if (start == end)		return tree[node];	int mid = start + (end - start) / 2;	int left_node = node * 2 + 1;	int right_node = node * 2 + 2;	int sum_left = query_tree(arr, tree, left_node, start, mid, L, R);	int sum_right = query_tree(arr, tree, right_node, mid+1, end, L, R);	return sum_left + sum_right;}int main() {	int arr[] = { 1,3,5,7,9,11 };	int size = 6;	int tree[MAX_LEN] = { 0 };	build_tree(arr, tree, 0, 0, size - 1);	for (int i = 0; i < 15; i++)		printf("tree[%d]=%d\n", i, tree[i]);	printf("\n");	update_tree(arr, tree, 0, 0, size - 1, 4, 6);	for (int i = 0; i < 15; i++)		printf("tree[%d]=%d\n", i, tree[i]);	int s = query_tree(arr, tree, 0, 0, size - 1, 2, 5);	printf("%d\n", s);	return 0;}
    
   

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