#include <iostream> #include <vector> #include <algorithm> #include <string> #include <set> #include <queue> #include <map> #include <sstream> #include <cstdio> #include <cstring> #include <numeric> #include <cmath> #include <iomanip> #include <deque> #include <bitset> //#include <unordered_set> //#include <unordered_map> //#include <bits/stdc++.h> //#include <xfunctional> #define ll long long #define PII pair<int, int> using namespace std; int dir[5][2] = { { 0,1 } ,{ 0,-1 },{ 1,0 },{ -1,0 } ,{ 0,0 } }; const long long INF = 0x7f7f7f7f7f7f7f7f; const int inf = 0x3f3f3f3f; const double pi = 3.14159265358979; const int mod = 1e9 + 7; const int N = 2e5+5; //if(x<0 || x>=r || y<0 || y>=c) //1000000000000000000 inline ll read() { ll x = 0; bool f = true; char c = getchar(); while (c < '0' || c > '9') { if (c == '-') f = false; c = getchar(); } while (c >= '0' && c <= '9') x = (x << 1) + (x << 3) + (c ^ 48), c = getchar(); return f ? x : -x; } int A[100000] = { 0,1,2,3,4,5,6 }; int tree[N]; void build(int node, int start, int end) { if (start == end) { // Leaf node will have a single element tree[node] = A[start]; } else { int mid = (start + end) / 2; // Recurse on the left child build(2 * node, start, mid); // Recurse on the right child build(2 * node + 1, mid + 1, end); // Internal node will have the sum of both of its children tree[node] = tree[2 * node] + tree[2 * node + 1]; } } void update(int node, int start, int end, int idx, int val) { if (start == end) { // Leaf node A[idx] += val; tree[node] += val; } else { int mid = (start + end) / 2; if (start <= idx && idx <= mid) { // If idx is in the left child, recurse on the left child update(2 * node, start, mid, idx, val); } else { // if idx is in the right child, recurse on the right child update(2 * node + 1, mid + 1, end, idx, val); } // Internal node will have the sum of both of its children tree[node] = tree[2 * node] + tree[2 * node + 1]; } } int query(int node, int start, int end, int l, int r) { if (r < start || end < l) { // range represented by a node is completely outside the given range return 0; } if (l <= start && end <= r) { // range represented by a node is completely inside the given range return tree[node]; } // range represented by a node is partially inside and partially outside the given range int mid = (start + end) / 2; int p1 = query(2 * node, start, mid, l, r); int p2 = query(2 * node + 1, mid + 1, end, l, r); return (p1 + p2); } int main() { int size = 6; build(1, 1, size); int res=query(1, 1, size, 2, 3); cout << res<<endl; return 0; }