Update fenwick_tree_2d.cpp

Changes

1 changed files (+14/-14)

• Data Structures/fenwick_tree_2d.cpp
  • @@ -1,21 +1,21 @@
    class fenwick_tree_2d { private: int N, M, vector<vector<int>> FT; public: - fenwick_tree_2d(int n, int m) { - N = n + 1, M = m + 1; - FT.resize(N, 0); - for (int i = 0; i < N; i++) FT[i].resize(M, 0); - } - void update(int x, int y, int val) { - for (int i = x; i < N; i += i & -i) { - for (int j = y; j < M; j += j & -j) FT[i][j] += val; + fenwick_tree_2d(int n, int m) { + N = n + 1, M = m + 1; + FT.resize(N, 0); + for (int i = 0; i < N; i++) FT[i].resize(M, 0); + } + void update(int x, int y, int val) { + for (int i = x; i < N; i += i & -i) { + for (int j = y; j < M; j += j & -j) FT[i][j] += val; } } - int query(int x, int y) { - int ret = 0; - for (int i = x; i > 0; i -= i & -i) { - for (int j = y; j > 0; j -= j & -j) ret += FT[i][j]; + int query(int x, int y) { + int ret = 0; + for (int i = x; i > 0; i -= i & -i) { + for (int j = y; j > 0; j -= j & -j) ret += FT[i][j]; } - return ans; - } + return ret; + } }