# Python Program to Find Maximum Scalar Product of Two Vectors in an Array

## Maximum Scalar Product of two Vectors in Python

Here, in this page we will discuss the program to find the maximum scalar product of two vectors in python programming language. Scalar product is also known as dot product. We are given with two vectors and need to print the maximum dot product obtained. ## Methods Discussed :

• Method 1 : Without Using Inbuilt sort() function.
• Method 2 : Using sort() function.

## Method 1 :

• Sort the first and second array in ascending order.
• Declare a variable say product = 0.
• Run a loop from index 0 to n
• Set product += (arrr1[i]*arr2[i])
• After complete iteration print product.

### Time and Space Complexity :

• Time Complexity : O(n2)
• Space Complexity : O(1)

### Method 1 : Code in Python

Run
```arr1 = [1, 2, 6, 3, 7]
arr2 = [10, 7, 45, 3, 7]

n = len(arr1)

#Sort arr1 in ascending order
for i in range(n):
for j in range(i+1, n):
if arr1[i]>arr1[j] :
arr1[i], arr1[j] = arr1[j], arr1[i]

#Sort arr2 in ascending order
for i in range(n):
for j in range(i+1, n):
if arr2[i]>arr2[j] :
arr2[i], arr2[j] = arr2[j], arr2[i]

product = 0
for i in range(n):
product += arr1[i]*arr2[i]

print(product)

```

```413
```

## Method 2 :

In this method we will use inbuilt sort function to sort the array.

• For, sorting arr1 in ascending order, use arr1.sort()
• For, sorting arr2 in ascending order, use arr2.sort(). ### Method 2 : Code in Python

Run
```arr1 = [1, 2, 6, 3, 7]
arr2 = [10, 7, 45, 3, 7]
n = len(arr1)

#Sort arr1 in ascending order
arr1.sort()

#Sort arr2 in ascending order
arr2.sort()

product = 0
for i in range(n):
product += arr1[i]*arr2[i]

print(product)```

### Output:

`413` ### One comment on “Python Program to Find Maximum Scalar Product of Two Vectors in an Array”

• Sanjeet

//Try this in C:
#include
int InsertionSort(int *,int);
int main()
{
int arrX,arrY,n,i,j,total=0;
printf(“Enter the length of array: “);
scanf(“%d”,&n);
printf(“Enter the value in arrayX: “);
for(i=0;i<n;i++)
{
scanf("%d",&arrX[i]);
}
printf("Enter the value in arrayY: ");
for(i=0;i<n;i++)
{
scanf("%d",&arrY[i]);
}
InsertionSort(arrX,n);
InsertionSort(arrY,n);
for(i=0;i<n;i++)
{
total=total+arrX[i]*arrY[i];
}
printf("The result is: %d",total);
return 0;
}
int InsertionSort(int *arr,int n)
{
int temp,pos,i;
for(i=1;i<n;i++)
{
temp=arr[i];
pos=i-1;
while(temp=0)
{
arr[pos+1]=arr[pos];
pos=pos-1;
}
arr[pos+1]=temp;
}
return 0;
} 0