A binary tree is left-complete of height h if all possible nodes of depth h-1 are present and all nodes at depth h are in the leftmost possible positions
size, complete binary tree 1 0 2 0 / 1 3 0 / \ 1 2 4 0 / \ 1 2 / 3 6 0 / \ 1 2 / \ / 3 4 5 7 0 / \ 1 2 / \ / \ 3 4 5 6 10 _ 0 _ / \ 1 2 / \ / \ 3 4 5 6 / \ / 7 8 9 15 _ 0 _ / \ 1 2 / \ / \ 3 4 5 6 / \ /\ / \ / \ 7 8 9 10 11 12 13 14 16 ________ 0 _______ / \ __ 1 __ __ 2 __ / \ / \ 3 4 5 6 / \ / \ / \ / \ 7 8 9 10 11 12 13 14 / 15 31 ________ 0 _______ / \ __ 1 __ __ 2 __ / \ / \ 3 4 5 6 / \ / \ / \ / \ 7 8 9 10 11 12 13 14 / \ / \ / \ / \ / \ / \ / \ / \ 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Height, range of sizes -1 0..0 0 1..1 1 2..3 2 4..7 3 8..15 4 16..31 5 32..63 6 64..127 7 128..255 8 256..511 9 512..1023 10 1024..2047 11 2048..4095 12 4096..8191 13 8192..16383 14 16384..32767 15 32768..65537 16 65536..131071 17 131072..262143 18 262144..523287 19 524288..1048575 20 1048576..(2 million +) .. 30 (1 billion +)..(2 billion +)h (2h) .. (2*2h - 1)