P D * 的取值范围
D1的取值
0 ≤ P D * < 2 k + 1 ( k + 1 ) 2
k 2 + k − 2 k + 2 − P * ( k 2 + 2 k + 2 ) k 2 + 2 k + 2
2 k + 1 ( k + 1 ) 2 ≤ P D * < 2 k + 2 k 2 + 2 k + 2
k 2 + k ± 2 k + 2 − P * ( k 2 + 2 k + 2 ) k 2 + 2 k + 2
P D * = 2 k + 2 k 2 + 2 k + 2
k 2 + k k 2 + 2 k + 2
P * > 2 k + 2 k 2 + 2 k + 2
( k + 1 ) 1 − P * k 2 + 2 k + 2