Find the smallest number in the rotation array in C++

Interview question: rotate the smallest number in an array

Title: to move the first elements of an array to the end of the array, we call the rotation of the array. Input a rotation of an incrementing array and output the smallest element of the array. For example, the array {3,4,5,1,2} is one rotation of {1,2,3,4,5}, and the minimum value of the array is 1.

Algorithm:

(1) when the input rotation array is illegal: processing!
(2) when the input rotation array is normal, index1 = 0; index2 = length - 1:

a: if arry [index1] < When arry[index2] : indicates that the array is the original array and is not rotated;
b: if arry [index1] > When = arry[index2], middle = (index1+index2) /2:

b. 1 if arry [index1] > arry[middle],index2 = middle;
b. 2 if arry [index1] < = arry[middle],index1 = middle;
b.3 if arry[index1] = arry[middle] = arry[index2], traverse to find the minimum.

Code:

Min_RotateArray.hpp

#pragma once 
#include<iostream> 
using namespace std; 
 
int Min_RotateArray(int arry[],int size) 
{ 
  if(arry == NULL || size <= 0) 
  {cout<<" Parameter input error!! "<<endl;} 
  int min = 0; 
  int index1 = 0; 
  int index2 = size-1; 
  int middle = (index1+index2)/2; 
  if(arry[0] < arry[size-1]) 
    return arry[0]; 
  while(arry[index1] >= arry[index2]) 
  { 
    if(index2-index1 == 1) 
    { 
      min=index2; 
      break; 
       
    } 
    middle = (index1+index2)/2; 
    if(arry[index1] <= arry[middle])//arry[middle] Also in the first 1 In an increasing sequence  
    { 
      index1 = middle; 
    } 
    else             
    { 
      if(arry[index1] >= arry[middle])//arry[middle] In the first 2 In an increasing sequence  
      {index2 = middle;} 
       
      if(arry[index1] == arry[index2] && arry[index1] == arry[middle]) 
      { 
        for(int i=0;i<size;++i) 
        { 
          if(arry[min]>arry[i]) 
            { 
              min = i; 
              break; 
            } 
        } 
 
      } 
    } 
  } 
  return arry[min]; 
} 

Min_RotateArray.cpp

#include"Min_RotateArray.hpp" 
 
int main() 
{ 
  int arry[] = {3,4,5,1,2}; 
  int size = sizeof(arry)/sizeof(arry[0]); 
  int min = Min_RotateArray(arry,size); 
  cout<<"The min is:"<<min<<endl; 
  system("pause"); 
  return 0; 
} 

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