查找按字典顺序排列的最小旋转序列的 PHP 程序设置 2

编写代码以查找圆形数组中的字典最小值，例如对于数组 BCABDADAB，字典最小值为 ABBCABDAD
输入约束：1 < n < 1000
例子：

Input:  GEEKSQUIZ
Output: EEKSQUIZG

Input:  GFG
Output: FGG

Input :  CAPABCQ
Output : ABCQCAP

我们已经讨论了字典最小字符串旋转中的 O(n ² Logn) 解决方案 |设置1。这里我们需要找到最小旋转的起始索引，然后打印旋转。

1) Initially assume 0 to be current min 
   starting index.
2) Loop through i = 1 to n-1.
   a) For each i compare sequence starting 
      at i with current min starting index
   b) If sequence starting at i is lexicographically 
      smaller, update current min starting 
      index.

这是算法的伪代码

function findIndexForSmallestSequence(S, n):
    result = 0
    for i = 1:n-1
        if (sequence beginning at i < 
               sequence beginning at result)
            result = i
        end if
    end for
    return result

这是上述算法的实现。

PHP

 $S[$y])
            return true;
        $x = ($x + 1) % $n;
        $y = ($y + 1) % $n;
    }
    return true;
}
  
// Function to find starting index
// of lexicographically smallest
// sequence
function smallestSequence($S, $n)
{
    $index = 0;
    for ( $i = 1; $i < $n; $i++)
  
        // if new sequence is smaller
        if (compareSeq($S, $index, $i, $n))
  
            // change index of current min
            $index = $i;
  
    return $index;
}
  
// Function to print lexicographically
// smallest sequence
function printSmallestSequence($S, $n)
{
    $starting_index = smallestSequence($S, $n);
    for ($i = 0; $i < $n; $i++)
        echo $S[($starting_index + $i) % $n];
}
  
    // Driver Code
    $S= "DCACBCAA";
    $n = 8;
    printSmallestSequence($S, $n);
  
// This code is contributed by Ajit.
?>

输出：

AADCACBC

时间复杂度： O(n^2)
辅助空间： O(1)
请参阅有关按字典顺序排列的最小旋转序列的完整文章 |设置2了解更多详情！