Dp decadent to the normal version of the definition and explanation of yzh
Consider the issue of random selection between a portion that the same number, the required part of the final position
Due to the overall complexity and n considering a relatively small number of considerations for each run to merge, provided g [i] [j] denotes the probability of the left and right hands, respectively, i, j is
Then the probability of occurrence of a situation that would put the number and which can also be learned
F array and then set to a seek answers, f [i] [j] denotes the probability for the number of partition number of the currently processed node i on the j
To the push-start f [k] [pos] = 1; then f [k] [i-1 + j-mid] [j] = f [k << 1] [i] * g [i] [j] * fir + f [k << 1 | 1] [j] * g [i] [j] * sec;
fir and sec determined by the result of the comparison is 1 or 0 or 0.5.
The probability of occurrence of the situation finalized
Consider a situation fixing do in complex situations
Do not memset, f array is large and with or without memory.