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Full Permutation

Algorithm tags ： Array 、 to flash back

Give us a sequence of numbers without repeating numbers , Let's find its total permutation

The implementation of recursive search

Search in what order , There are many search orders for ranking problems

① We can enumerate which number to fill in for each position from front to back , You can enumerate which number to fill in the first position , Then enumerate which number to fill in the second position , And so on √

② Enumerate the position of each number in turn , The first number can be placed on the 0 In a position , You can put it in the 1 You can also put it in the... Position 2 In a position , The second number can be put in the 0 In a position , You can put it in the 1 You can also put it in the... Position 2 In a position

For the permutation problem , The above two search orders are OK

The recursive search tree of the first scheme is given below , Each leaf node represents a scheme