reset的博客

Matrix （POJ - 2155 ）Given an N*N matrix A, whose elements are either 0 or 1. A[i, j] means the number in the i-th row and j-th column. Initially we have A[i, j] = 0 (1 <= i, j <= N). We can change the matrix in the following way. Given a rectangle whose

树状数组的修改与查询总结树状数组的单点修改区间查询树状数组的区间修改单点查询树状数组的区间修改区间查询