LintCode 654 · Sparse Matrix Multiplication (稀疏矩阵乘法)
654·SparseMatrixMultiplicationAlgorithmsDescriptionGiventwoSparseMatrixAandB,returntheresultofAB.YoumayassumethatA’scolumnnumberisequaltoB’srownumber.ExampleExample1Input:[[1,0,0],[-1,0,3]][[7,0,0],[0