The way the matrix addition is written is very close to the way we express this relation mathematically. The benefit for the programmer is that our code is easier to read. Furthermore, such a way of coding makes it more likely to spot eventual errors as well.
In Ansi C and C++ arrays start by default from \( i=0 \). Moreover, if we wish to add two matrices we need to explicitely write out the two loops as
for(i=0 ; i < n ; i++) {
for(j=0 ; j < n ; j++) {
a[i][j]=b[i][j]+c[i][j]