Need clarification about array syntax

Question

What is the difference between declaring a 2D array in C++ like this:

int mp[3][3]={{0,2,1},
              {0,2,1},
              {1,2,0}};

And this?

int mp[3][3]={0,2,1,
              0,2,1,
              1,2,0};

Is the above an array where all 3 elements are arrays themselves while the bottom one is an array of non-array elements or are both read by the compiler as the same?

Answer 1

They're equivalent. The first one is a completely braced form. When the interpretation is unambiguous (such as in the second form), the standard allows eliding the braces.

Answer 2

Both are same you can access elements for matrix using following loop:

for (i=0;i<3;i++)   
     for(j=0;j<3;j++)     
        printf("%d ",mp[i][j] );

One difference in when you give braces in first case then first argument can be omitted like:

int mp[][3]={{0,2,1},
              {0,2,1},
              {1,2,0}};

But C++ compiler will give you warning: missing braces around for second type of declaration.

EDIT:
As you commented: my program was giving me different results

I have written a code. working fine on C++ (gcc-4.7.2). Check here