A computer implemented system comprises: a tangible, non-transitory computer readable storage medium encoded with data representing an initial layout of an integrated circuit pattern layer having a plurality of polygons. A special-purpose computer is configured to perform the steps of: analyzing in the initial layout of an integrated circuit pattern layer having a plurality of polygons, so as to identify a plurality of multi-patterning conflict cycles in the initial layout; constructing in the computer a respective multi-patterning conflict cycle graph representing each identified multi-patterning conflict cycle; classifying each identified multi-patterning conflict cycle graph in the computer according to a number of other multi-patterning conflict cycle graphs which enclose that multi-patterning conflict cycle graph; and causing a display device to graphically display the plurality of multi-patterning conflict cycle graphs according to their respective classifications.