Python | Maximum sum of elements of list in a list of lists

Given lists in a list, find the maximum sum of elements of list in a list of lists. Examples:

Input :  [[1, 2, 3], [4, 5, 6], [10, 11, 12], [7, 8, 9]]
Output : 33 
Explanation: sum of all lists in the given list of lists are:
             list1 = 6, list2 = 15, list3 = 33, list4 = 24 
             so the maximum among these is of 

Input : [[3, 4, 5], [1, 2, 3], [0, 9, 0]]
Output : 12

Method 1 : Traversal of list in lists

We can traverse in the lists inside the list and sum up all the elements in a given list and by max function get the maximum of sum of all elements in lists of list. 

Python

# Python program to find the
# list in a list of lists whose
# sum of elements is the highest
# using traversal

def maximumSum(list1):
    maxi = 0

    # traversal in the lists
    for x in list1:
        sum = 0
        # traversal in list of lists
        for y in x:
            sum+= y
        maxi = max(sum, maxi)

    return maxi

# driver code
list1 = [[1, 2, 3], [4, 5, 6], [10, 11, 12], [7, 8, 9]]
print maximumSum(list1)

Output:

33

Time Complexity: O(n*m) where n is the number of lists and m is the maximum size of the list.
Auxiliary Space: O(1)

Method 2 : Traversal of list

Traverse in the outer list only, and sum all elements in the inner lists by using sum() function, find the sum of all the lists and get the maximum of all the sum calculated. 

Python

# Python program to find the
# list in a list of lists whose
# sum of elements is the highest
# using sum and max function and traversal

def maximumSum(list1):
    maxi = 0
    # traversal
    for x in list1:
        maxi = max(sum(x), maxi)

    return maxi


# driver code
list1 = [[1, 2, 3], [4, 5, 6], [10, 11, 12], [7, 8, 9]]
print maximumSum(list1)

Output:

33

Time Complexity: O(n*m) where n is the number of lists and m is the maximum size of the list.
Auxiliary Space: O(1)

Method 3 : Sum and Max function

sum(max(list1, key=sum))

The above syntax of max() function allows us to find the sum of list in list using the key=sum. max(list1, key=sum), this finds the list with maximum sum of elements and then sum(max(list1, key=sum)) returns us the sum of that list. 

Python

# Python program to find the
# list in a list of lists whose
# sum of elements is the highest
# using sum and max function

def maximumSum(list1):
    return(sum(max(list1, key = sum)))


# driver code
list1 = [[1, 2, 3], [4, 5, 6], [10, 11, 12], [7, 8, 9]]
print maximumSum(list1)

Output:

33

Time Complexity: O(n*m) where n is the number of lists and m is the maximum size of the list.
Auxiliary Space: O(1)