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author | Jack Sangdahl <[email protected]> | 2025-03-10 00:36:13 -0600 |
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committer | Jack Sangdahl <[email protected]> | 2025-03-10 00:36:13 -0600 |
commit | 7c60dee83b436e8e8a667bf9f191beced8de4fc3 (patch) | |
tree | eb7a24ee2067f92245c57bb118e85a1baf15df50 /other/range_sum_query_mutable.cpp | |
parent | 5d7cdc215e4ba1ec4cbb24c084cccb5e5e641468 (diff) | |
download | leetcode-7c60dee83b436e8e8a667bf9f191beced8de4fc3.tar.gz leetcode-7c60dee83b436e8e8a667bf9f191beced8de4fc3.zip |
chore: move cpp and rust code to directory
Diffstat (limited to 'other/range_sum_query_mutable.cpp')
-rw-r--r-- | other/range_sum_query_mutable.cpp | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/other/range_sum_query_mutable.cpp b/other/range_sum_query_mutable.cpp new file mode 100644 index 0000000..cdc0230 --- /dev/null +++ b/other/range_sum_query_mutable.cpp @@ -0,0 +1,61 @@ +#include "leetcode.h" + +struct segNode { + int start, end, sum; + segNode *left, *right; + segNode(int a, int b) + : start(a), end(b), sum(0), left(nullptr), right(nullptr) {} +}; + +class NumArray { +public: + segNode *root; + NumArray(vector<int> &nums) { root = buildTree(nums, 0, nums.size() - 1); } + void update(int index, int val) { modifyTree(index, val, root); } + int sumRange(int left, int right) { return queryTree(left, right, root); } + +private: + segNode *buildTree(vector<int> &nums, int start, int end) { + if (start > end) + return nullptr; + segNode *root = new segNode(start, end); + if (start == end) { + root->sum = nums[start]; + return root; + } + int mid = start + (end - start) / 2; + root->left = buildTree(nums, start, mid); + root->right = buildTree(nums, mid + 1, end); + root->sum = root->left->sum + root->right->sum; + return root; + } + int modifyTree(int i, int val, segNode *root) { + if (root == nullptr) + return 0; + int diff; + if (root->start == i && root->end == i) { + diff = val - root->sum; + root->sum = val; + return diff; + } + int mid = (root->start + root->end) / 2; + if (i > mid) + diff = modifyTree(i, val, root->right); + else + diff = modifyTree(i, val, root->left); + root->sum = root->sum + diff; + return diff; + } + int queryTree(int i, int j, segNode *root) { + if (root == nullptr) + return 0; + if (root->start == i && root->end == j) + return root->sum; + int mid = (root->start + root->end) / 2; + if (i > mid) + return queryTree(i, j, root->right); + if (j <= mid) + return queryTree(i, j, root->left); + return queryTree(i, mid, root->left) + queryTree(mid + 1, j, root->right); + } +}; |