一个阵列的所有子阵列的乘积

原文:https://www . geeksforgeeks . org/全阵列子阵列产品/

给定一个整数数组 arr 的大小 N ,任务是打印数组的所有子数组的产品。

示例:

输入: arr[] = {2,4 } T3】输出: 64 这里,子阵是【2】、【2,4】、【4】 积是所有子阵的 2,8,4 积= 64

输入: arr[] = {10,3,7} 输出: 27783000 这里,子阵是[10],[10,3],[10,3,7],[3,7],[7] 产品是所有子阵的 10,30,210,3,21,7 产品= 27783000

天真方法:一个简单的解决方案是生成所有子阵列并计算它们的乘积。

C++

// C++ program to find product
// of all subarray of an array

#include <bits/stdc++.h>
using namespace std;

// Function to find product of all subarrays
void product_subarrays(int arr[], int n)
{
    // Variable to store the product
    int product = 1;

    // Compute the product while
    // traversing for subarrays
    for (int i = 0; i < n; i++) {
        for (int j = i; j < n; j++) {
            for (int k = i; k <= j; k++)
                product *= arr[k];
        }
    }

    // Printing product of all subarray
    cout << product << "\n";
}

// Driver code
int main()
{
    int arr[] = { 10, 3, 7 };

    int n = sizeof(arr) / sizeof(arr[0]);

    // Function call
    product_subarrays(arr, n);

    return 0;
}

Java 语言(一种计算机语言,尤用于创建网站)

// Java program to find product
// of all subarray of an array
import java.util.*;

class GFG {

    // Function to find product of all subarrays
    static void product_subarrays(int arr[], int n)
    {

        // Variable to store the product
        int product = 1;

        // Compute the product while
        // traversing for subarrays
        for (int i = 0; i < n; i++) {
            for (int j = i; j < n; j++) {
                for (int k = i; k <= j; k++)
                    product *= arr[k];
            }
        }

        // Printing product of all subarray
        System.out.print(product + "\n");
    }

    // Driver code
    public static void main(String args[])
    {
        int arr[] = { 10, 3, 7 };
        int n = arr.length;

        // Function call
        product_subarrays(arr, n);
    }
}

// This code is contributed by shivanisinghss2110

Python 3

# Python3 program to find product
# of all subarray of an array

# Function to find product of all subarrays
def product_subarrays(arr, n):

    # Variable to store the product
    product = 1;

    # Compute the product while
    # traversing for subarrays
    for i in range(0, n):
        for j in range(i, n):
            for k in range(i, j + 1):
                product *= arr[k];

    # Printing product of all subarray
    print(product, "\n");

# Driver code
arr = [ 10, 3, 7 ];

n = len(arr);

# Function call
product_subarrays(arr, n);

# This code is contributed by Code_Mech

C

// C# program to find product
// of all subarray of an array
using System;

class GFG {

    // Function to find product of all subarrays
    static void product_subarrays(int[] arr, int n)
    {

        // Variable to store the product
        int product = 1;

        // Compute the product while
        // traversing for subarrays
        for (int i = 0; i < n; i++) {
            for (int j = i; j < n; j++) {
                for (int k = i; k <= j; k++)
                    product *= arr[k];
            }
        }

        // Printing product of all subarray
        Console.Write(product + "\n");
    }

    // Driver code
    public static void Main(String[] args)
    {
        int[] arr = { 10, 3, 7 };
        int n = arr.Length;

        // Function call
        product_subarrays(arr, n);
    }
}

// This code is contributed by shivanisinghss2110

java 描述语言

<script>
  // Javascript program to find product
  // of all subarray of an array

  // Function to find product of all subarrays
  function product_subarrays(arr, n)
  {

      // Variable to store the product
      let product = 1;

      // Compute the product while
      // traversing for subarrays
      for (let i = 0; i < n; i++) {
          for (let j = i; j < n; j++) {
              for (let k = i; k <= j; k++)
                  product *= arr[k];
          }
      }

      // Printing product of all subarray
      document.write(product + "</br>");
  }

  let arr = [ 10, 3, 7 ];
  let n = arr.length;

  // Function call
  product_subarrays(arr, n);

// This code is contributed by divyeshrabadiya07.
</script>

Output: 

27783000

时间复杂度:O(n 3 )

辅助空间:0(1)

有效方法:一种有效方法是使用两个循环并在遍历子阵列时计算乘积。 以下是上述办法的实施情况:

C++

// C++ program to find product
// of all subarray of an array

#include <bits/stdc++.h>
using namespace std;

// Function to find product of all subarrays
void product_subarrays(long long int arr[], int n)
{
    // Variable to store the product
    long long int res = 1;

    // Compute the product while
    // traversing for subarrays
    for (int i = 0; i < n; i++) {
        long long int product = 1;
        for (int j = i; j < n; j++) {
            product = product * arr[j];
            res *= product;
        }
    }
    // Printing product of all subarray
    cout << res << "\n";
}

// Driver code
int main()
{
    long long int arr[] = { 10, 3, 7 };

    int n = sizeof(arr) / sizeof(arr[0]);

    // Function call
    product_subarrays(arr, n);

    return 0;
}

Java 语言(一种计算机语言,尤用于创建网站)

// Java program to find product
// of all subarray of an array
import java.util.*;

class GFG {

    // Function to find product of all subarrays
    static void product_subarrays(int arr[], int n)
    {
        // Variable to store the product
        int res = 1;

        // Compute the product while
        // traversing for subarrays
        for (int i = 0; i < n; i++) {
            int product = 1;
            for (int j = i; j < n; j++) {
                product = product * arr[j];
                res *= product;
            }
        }

        // Printing product of all subarray
        System.out.println(res + "\n");
    }

    // Driver code
    public static void main(String args[])
    {
        int arr[] = { 10, 3, 7 };

        int n = arr.length;

        // Function call
        product_subarrays(arr, n);
    }
}

// This code is contributed by AbhiThakur

Python 3

# Python3 program to find product
# of all subarray of an array

# Function to find product of all subarrays
def product_subarrays(arr, n):

    # Variable to store the product
    res = 1;

    # Compute the product while
    # traversing for subarrays
    for i in range(n):
        product = 1
        for j in range(i, n):
            product *= arr[j];
            res = res * product

    # Printing product of all subarray
    print(res);

# Driver code
if __name__ == '__main__':
    arr = [ 10, 3, 7 ];

    n = len(arr);

    # Function call
    product_subarrays(arr, n);

# This code is contributed by Princi Singh

C

// C# program to find product
// of all subarray of an array
using System;

class GFG {

    // Function to find product of all subarrays
    static void product_subarrays(int[] arr, int n)
    {
        // Variable to store the product
        int res = 1;

        // Compute the product while
        // traversing for subarrays
        for (int i = 0; i < n; i++) {
            int product = 1;
            for (int j = i; j < n; j++) {
                product *= arr[j];
                res = res * product;
            }
        }

        // Printing product of all subarray
        Console.WriteLine(res + "\n");
    }

    // Driver code
    public static void Main(String[] args)
    {
        int[] arr = { 10, 3, 7 };

        int n = arr.Length;

        // Function call
        product_subarrays(arr, n);
    }
}

// This code is contributed by 29AjayKumar

java 描述语言

<script>

// Javascript program to find product
// of all subarray of an array

// Function to find product of all subarrays
function product_subarrays(arr, n)
{
    // Variable to store the product
    var res = 1;

    // Compute the product while
    // traversing for subarrays
    for (var i = 0; i < n; i++) {
        var product = 1;
        for (var j = i; j < n; j++) {
            product = product * arr[j];
            res *= product;
        }
    }
    // Printing product of all subarray
    document.write( res );
}

// Driver code
var arr = [10, 3, 7];
var n = arr.length;
// Function call
product_subarrays(arr, n);

</script>

Output: 

27783000

时间复杂度:O(n 2 )

辅助空间:0(1)