How to choose positions for snake grouping

Serpentine grouping method: firstly, the athletes are ranked according to their achievements, and then according to the number of groups that need to be ranked, the athletes are arranged into different groups according to the serpentine trend; If there are many athletes from the same unit in the same group, they can only adjust up and down nearby, and then draw lots to arrange the competition order of each group and the athletes' competition passes.

Divide the whole figure diagonally, and only look at the left half. Diagonal parity is determined by e=(%%a+%%b)%%2.

Extract the smallest number in each diagonal, namely1247111622 29 35. This second-order arithmetic progression can be calculated by (n- 1)*n/2+ 1. Batch processing is (a+b-1-1) * (b-1+a)/2+1.

We extract the largest numbers in each diagonal, which are136101521283645. This second-order arithmetic progression can be calculated by (n+ 1)*n/2. Batch processing is (a+b-1+1) * (b-1+a)/2.