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Поделити низ на два подниза тако да су њихови просеци једнаки

Задат целобројни низ задатак је да се цели број подели на два подниза да би њихови просеци били једнаки ако је могуће.

Примери:  

ц стринг у низу
Input : arr[] = {1 5 7 2 0}; Output : (0 1) and (2 4) Subarrays arr[0..1] and arr[2..4] have same average. Input : arr[] = {4 3 5 9 11}; Output : Not possible

Питано у Мицрософту 



А Наиве Аппроацх је покренути две петље и пронаћи поднизе чији су просеци једнаки. 

Имплементација:

C++
// Simple C++ program to find subarrays // whose averages are equal #include   using namespace std; // Finding two subarrays // with equal average. void findSubarrays(int arr[] int n) {  bool found = false;  int lsum = 0;  for (int i = 0; i < n - 1; i++)  {  lsum += arr[i];  int rsum = 0;  for (int j = i + 1; j < n; j++)  rsum += arr[j];  // If averages of arr[0...i] and   // arr[i+1..n-1] are same. To avoid  // floating point problems we compare   // 'lsum*(n-i+1)' and 'rsum*(i+1)'   // instead of 'lsum/(i+1)' and   // 'rsum/(n-i+1)'  if (lsum * (n - i - 1) ==   rsum * (i + 1))  {  printf('From (%d %d) to (%d %d)n'  0 i i + 1 n - 1);  found = true;  }  }  // If no subarrays found  if (found == false)  cout << 'Subarrays not found'   << endl; } // Driver code int main() {  int arr[] = {1 5 7 2 0};  int n = sizeof(arr) / sizeof(arr[0]);  findSubarrays(arr n);  return 0; } 
Java
// Simple Java program to find subarrays // whose averages are equal public class GFG {    // Finding two subarrays  // with equal average.  static void findSubarrays(int[] arr int n)  {  boolean found = false;  int lsum = 0;    for (int i = 0; i < n - 1; i++)  {  lsum += arr[i];  int rsum = 0;    for (int j = i + 1; j < n; j++)  rsum += arr[j];    // If averages of arr[0...i] and   // arr[i+1..n-1] are same. To avoid  // floating point problems we compare   // 'lsum*(n-i+1)' and 'rsum*(i+1)'   // instead of 'lsum/(i+1)' and   // 'rsum/(n-i+1)'  if (lsum * (n - i - 1) ==   rsum * (i + 1))  {  System.out.println('From (0 ' + i   + ') to (' +(i + 1) + ' '  + (n - 1)+ ')');    found = true;  }  }    // If no subarrays found  if (found == false)  System.out.println( 'Subarrays not '  + 'found');  }    // Driver code  static public void main (String[] args)  {  int[] arr = {1 5 7 2 0};  int n = arr.length;  findSubarrays(arr n);  } } // This code is contributed by Mukul Singh. 
Python 3
# Simple Python 3 program to find subarrays # whose averages are equal # Finding two subarrays with equal average. def findSubarrays(arr n): found = False lsum = 0 for i in range(n - 1): lsum += arr[i] rsum = 0 for j in range(i + 1 n): rsum += arr[j] # If averages of arr[0...i] and  # arr[i+1..n-1] are same. To avoid # floating point problems we compare  # 'lsum*(n-i+1)' and 'rsum*(i+1)'  # instead of 'lsum/(i+1)' and  # 'rsum/(n-i+1)' if (lsum * (n - i - 1) == rsum * (i + 1)): print('From' '(' 0 i ')' 'to' '(' i + 1 n - 1 ')') found = True # If no subarrays found if (found == False): print('Subarrays not found') # Driver code if __name__ == '__main__': arr = [1 5 7 2 0] n = len(arr) findSubarrays(arr n) # This code is contributed by ita_c 
C#
// Simple C# program to find subarrays // whose averages are equal using System; public class GFG {    // Finding two subarrays  // with equal average.  static void findSubarrays(int []arr int n)  {  bool found = false;  int lsum = 0;    for (int i = 0; i < n - 1; i++)  {  lsum += arr[i];  int rsum = 0;    for (int j = i + 1; j < n; j++)  rsum += arr[j];    // If averages of arr[0...i] and   // arr[i+1..n-1] are same. To avoid  // floating point problems we compare   // 'lsum*(n-i+1)' and 'rsum*(i+1)'   // instead of 'lsum/(i+1)' and   // 'rsum/(n-i+1)'  if (lsum * (n - i - 1) ==   rsum * (i + 1))  {  Console.WriteLine('From ( 0 ' + i   + ') to(' + (i + 1) + ' '  + (n - 1) + ')');    found = true;  }  }    // If no subarrays found  if (found == false)  Console.WriteLine( 'Subarrays not '  + 'found');  }    // Driver code  static public void Main ()  {  int []arr = {1 5 7 2 0};  int n = arr.Length;  findSubarrays(arr n);  } } // This code is contributed by anuj_67. 
PHP
 // Simple PHP program to find subarrays // whose averages are equal // Finding two subarrays  // with equal average. function findSubarrays( $arr $n) { $found = false; $lsum = 0; for ( $i = 0; $i < $n - 1; $i++) { $lsum += $arr[$i]; $rsum = 0; for ( $j = $i + 1; $j < $n; $j++) $rsum += $arr[$j]; // If averages of arr[0...i] and  // arr[i+1..n-1] are same. To avoid // floating point problems we compare // 'lsum*(n-i+1)' and 'rsum*(i+1)' // instead of 'lsum/(i+1)' and 'rsum/(n-i+1)' if ($lsum * ($n - $i - 1) == $rsum * ($i + 1)) { echo 'From ( 0 ' $i' )'. ' to (' $i + 1' ' $n - 1')n'; $found = true; } } // If no subarrays found if ($found == false) echo 'Subarrays not found' ; } // Driver code $arr = array(1 5 7 2 0); $n = count($arr); findSubarrays($arr $n); // This code is contributed by vt_m ?> 
JavaScript
<script> // Simple Javascript program to find subarrays // whose averages are equal    // Finding two subarrays  // with equal average.  function findSubarrays(arrn)  {  let found = false;  let lsum = 0;    for (let i = 0; i < n - 1; i++)  {  lsum += arr[i];  let rsum = 0;    for (let j = i + 1; j < n; j++)  rsum += arr[j];    // If averages of arr[0...i] and   // arr[i+1..n-1] are same. To avoid  // floating point problems we compare   // 'lsum*(n-i+1)' and 'rsum*(i+1)'   // instead of 'lsum/(i+1)' and   // 'rsum/(n-i+1)'  if (lsum * (n - i - 1) ==   rsum * (i + 1))  {  document.write('From (0 ' + i   + ') to (' +(i + 1) + ' '  + (n - 1)+ ')');    found = true;  }  }    // If no subarrays found  if (found == false)  document.write( 'Subarrays not '  + 'found');  }    // Driver code  let arr=[1 5 7 2 0];  let n = arr.length;  findSubarrays(arr n);    // This code is contributed by avanitrachhadiya2155   </script>  

Излаз
From (0 1) to (2 4)

Временска сложеност : О(н2
Помоћни простор : О(1)

Ан Ефикасно решење је пронаћи збир елемената низа. Иницијализујте леви збир као нула. Покрените петљу и пронађите леви збир додавањем елемената низа. За Ригхтсум одузимамо леавесум од укупног збира, затим налазимо Ригхтсум и налазимо просек леве и Ригхтсум као Према њиховом индексу.

1) Compute sum of all array elements. Let this sum be 'sum' 2) Initialize leftsum = 0. 3) Run a loop for i=0 to n-1. a) leftsum = leftsum + arr[i] b) rightsum = sum - leftsum c) If average of left and right are same print current index as output.

Испод је имплементација горњег приступа:

јава руковање изузетцима
C++
// Efficient C++ program for  // dividing array to make  // average equal #include   using namespace std; void findSubarrays(int arr[] int n) {  // Find array sum  int sum = 0;  for (int i = 0; i < n; i++)  sum += arr[i];  bool found = false;  int lsum = 0;  for (int i = 0; i < n - 1; i++)  {  lsum += arr[i];  int rsum = sum - lsum;  // If averages of arr[0...i]   // and arr[i+1..n-1] are same.   // To avoid floating point problems  // we compare 'lsum*(n-i+1)'   // and 'rsum*(i+1)' instead of   // 'lsum/(i+1)' and 'rsum/(n-i+1)'  if (lsum * (n - i - 1) == rsum * (i + 1))  {  printf('From (%d %d) to (%d %d)n'  0 i i+1 n-1);  found = true;  }  }  // If no subarrays found  if (found == false)  cout << 'Subarrays not found'  << endl; } // Driver code int main() {  int arr[] = {1 5 7 2 0};  int n = sizeof(arr) / sizeof(arr[0]);  findSubarrays(arr n);  return 0; } 
Java
// Efficient Java program for  // dividing array to make  // average equal import java.util.*;   class GFG { static void findSubarrays(int arr[] int n) {  // Find array sum  int sum = 0;  for (int i = 0; i < n; i++)  sum += arr[i];  boolean found = false;  int lsum = 0;  for (int i = 0; i < n - 1; i++)  {  lsum += arr[i];  int rsum = sum - lsum;  // If averages of arr[0...i]   // and arr[i+1..n-1] are same.   // To avoid floating point problems  // we compare 'lsum*(n-i+1)'   // and 'rsum*(i+1)' instead of   // 'lsum/(i+1)' and 'rsum/(n-i+1)'  if (lsum * (n - i - 1) == rsum * (i + 1))  {  System.out.printf('From (%d %d) to (%d %d)n'  0 i i + 1 n - 1);  found = true;  }  }  // If no subarrays found  if (found == false)  System.out.println('Subarrays not found'); } // Driver code static public void main ( String []arg) {  int arr[] = {1 5 7 2 0};  int n = arr.length;  findSubarrays(arr n); } } // This code is contributed by Princi Singh 
Python3
# Efficient Python program for  # dividing array to make  # average equal def findSubarrays(arr n): # Find array sum sum = 0; for i in range(n): sum += arr[i]; found = False; lsum = 0; for i in range(n - 1): lsum += arr[i]; rsum = sum - lsum; # If averages of arr[0...i] # and arr[i + 1..n - 1] are same. # To avoid floating point problems # we compare 'lsum*(n - i + 1)' # and 'rsum*(i + 1)' instead of # 'lsum / (i + 1)' and 'rsum/(n - i + 1)' if (lsum * (n - i - 1) == rsum * (i + 1)): print('From (%d %d) to (%d %d)n'% (0 i i + 1 n - 1)); found = True; # If no subarrays found if (found == False): print('Subarrays not found'); # Driver code if __name__ == '__main__': arr = [ 1 5 7 2 0 ]; n = len(arr); findSubarrays(arr n); # This code is contributed by Rajput-Ji 
C#
// Efficient C# program for  // dividing array to make  // average equal using System;   class GFG { static void findSubarrays(int []arr int n) {  // Find array sum  int sum = 0;  for (int i = 0; i < n; i++)  sum += arr[i];  bool found = false;  int lsum = 0;  for (int i = 0; i < n - 1; i++)  {  lsum += arr[i];  int rsum = sum - lsum;  // If averages of arr[0...i]   // and arr[i+1..n-1] are same.   // To avoid floating point problems  // we compare 'lsum*(n-i+1)'   // and 'rsum*(i+1)' instead of   // 'lsum/(i+1)' and 'rsum/(n-i+1)'  if (lsum * (n - i - 1) == rsum * (i + 1))  {  Console.Write('From ({0} {1}) to ({2} {3})n'  0 i i + 1 n - 1);  found = true;  }  }  // If no subarrays found  if (found == false)  Console.WriteLine('Subarrays not found'); } // Driver code static public void Main ( String []arg) {  int []arr = {1 5 7 2 0};  int n = arr.Length;  findSubarrays(arr n); } }   // This code is contributed by Rajput-Ji 
JavaScript
<script> // Efficient Javascript program for // dividing array to make // average equal    function findSubarrays(arrn)  {  // Find array sum  let sum = 0;  for (let i = 0; i < n; i++)  sum += arr[i];  let found = false;  let lsum = 0;  for (let i = 0; i < n - 1; i++)  {  lsum += arr[i];  let rsum = sum - lsum;  // If averages of arr[0...i]  // and arr[i+1..n-1] are same.  // To avoid floating point problems  // we compare 'lsum*(n-i+1)'  // and 'rsum*(i+1)' instead of  // 'lsum/(i+1)' and 'rsum/(n-i+1)'  if (lsum * (n - i - 1) == rsum * (i + 1))  {  document.write(  'From (0 '+i+') to ('+(i+1)+' '+(n-1)+')n'  );    found = true;  }  }  // If no subarrays found  if (found == false)  document.write('Subarrays not found');  }  // Driver code  let arr=[1 5 7 2 0];  let n = arr.length;  findSubarrays(arr n);    // This code is contributed by rag2127 </script> 

Излаз
From (0 1) to (2 4)

Временска сложеност: О(н) 
Помоћни простор : О(1)

 

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