Wavelet Tree · Rank in O(log σ)
unseel.com · σ=8 · log σ = 3 levels · n log σ bits
Sequence 12 chars
Query rank(c=5, i=8)
Stage sequence loaded
Bit = 0 (left half)
Bit = 1 (right half)
Active range / cursor
Answer
Unseel.com · Wavelet Tree