K Nearest Vector between two Vectors

Hello All, I Have three vectors, A, B and C. Each one is Mx1 elements. If A is the test vector (contains time samples), B and C are class 1 and 2, respectively. How can I apply K nearest neighbor, in order to classify vector A into either Class B or C ? can I make the comparison element-wise, that is, find euklidean distance between pairs [A(1),B(1)] and [A(1),C(1)] and pick the smallest one ?

thanks in advance for your support