Numerical controller and simulator thereof

A numerical controller of the present invention is a numerical controller for controlling a machine having two or more paths based on a machining program for a single path in which two or more tools are moved in a radial direction of the workpiece and a direction parallel to the axis of rotation to perform cutting, and includes path assignment means for dividing the machining program into cutting motion groups by using rapid motions as delimiters, assigning the cutting motion groups which are divided to the two or more paths, and generating path assignment information in which the cutting motion groups which are assigned are overlapped between a cutting motion group located earlier on the machining program and a cutting motion group located later such that a cutting position by the cutting motion group located later does not overtake a cutting position by the cutting motion group located earlier.