Source file src/github.com/thoas/go-funk/permutation.go

Documentation: github.com/thoas/go-funk

     1  package funk
     2  
     3  import "errors"
     4  
     5  // NextPermutation Implement next permutation,
     6  // which rearranges numbers into the lexicographically next greater permutation of numbers.
     7  func NextPermutation(nums []int) error {
     8  	n := len(nums)
     9  	if n == 0 {
    10  		return errors.New("nums is empty")
    11  	}
    12  
    13  	i := n - 2
    14  
    15  	for i >= 0 && nums[i] >= nums[i+1] {
    16  		i--
    17  	}
    18  
    19  	if i >= 0 {
    20  		j := n - 1
    21  		for j >= 0 && nums[i] >= nums[j] {
    22  			j--
    23  		}
    24  		nums[i], nums[j] = nums[j], nums[i]
    25  	}
    26  
    27  	ReverseInt(nums[i+1:])
    28  	return nil
    29  }
    30  

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