form another matrix with one extra layer of border elements . Border elements will contain INT_MIN value .
for i in range ( n + 2 ) : NEW_LINE INDENT for j in range ( n + 2 ) : NEW_LINE INDENT if ( ( i == 0 ) or ( j == 0 ) or ( i == n + 1 ) or ( j == n + 1 ) ) : NEW_LINE DEDENT DEDENT