n=4096 Q=2000000 reps=5 (ns/op, median [min, max])
  point add   fenwick                         10.1  [10.0, 10.4]
  point add   recursive segtree               46.2  [46.1, 47.8]
  point add   zkw                              4.3  [4.2, 4.6]
  range sum   fenwick                         14.6  [14.4, 15.0]
  range sum   recursive segtree              100.5  [99.8, 103.5]
  range sum   zkw                             56.0  [55.6, 57.3]
  range sum   zkw branchless                  12.0  [11.9, 12.5]
  range add   two fenwicks                    27.3  [25.9, 28.0]
  range add   lazy segtree                   174.6  [171.5, 177.0]
  range sum   two fenwicks (after adds)       18.8  [18.7, 19.7]
  range sum   lazy segtree (after adds)      110.7  [108.3, 115.9]
n=1000000 Q=2000000 reps=5 (ns/op, median [min, max])
  point add   fenwick                         30.9  [30.3, 31.9]
  point add   recursive segtree              113.7  [95.5, 124.5]
  point add   zkw                             31.7  [24.2, 32.5]
  range sum   fenwick                         38.8  [38.2, 39.7]
  range sum   recursive segtree              298.2  [270.4, 320.1]
  range sum   zkw                            112.3  [105.0, 119.3]
  range sum   zkw branchless                 136.7  [86.4, 150.6]
  range add   two fenwicks                   145.5  [141.1, 151.3]
  range add   lazy segtree                   661.0  [650.2, 679.3]
  range sum   two fenwicks (after adds)       98.6  [82.8, 105.4]
  range sum   lazy segtree (after adds)      372.9  [345.0, 438.8]