Java技术问题：负整数转正整数及数组行绝对值和最大值计算

Got it, let's break this down and fix up your existing method to meet the requirement.

First, recap what we need: we already have code that grabs each row from a 2D array and calculates row sums—we just need to tweak it to convert every negative number to its positive equivalent (take the absolute value) before summing the row. Then we just pick the largest sum from the adjusted list.

Step-by-Step Adjustment #

• For every element in a row, use your language's built-in absolute value function (like abs() in Python, Math.abs() in Java, Math.Abs() in C#) to make negative numbers positive
• Sum these adjusted values for each row (your existing row-summing logic stays almost the same—we just add this one layer of processing)
• Finally, find the maximum value from the list of absolute-value row sums

Example Code (Python) #

Let's say your existing row-summing method looks like this (without absolute value handling):

def get_row_sums(arr):
    row_sums = []
    for row in arr:
        row_sum = sum(row)  # Missing absolute value logic here
        row_sums.append(row_sum)
    return row_sums

We just modify the summation step to process each element with abs():

def get_absolute_row_sums(arr):
    row_sums = []
    for row in arr:
        # Sum the absolute value of each element in the row
        absolute_sum = sum(abs(num) for num in row)
        row_sums.append(absolute_sum)
    return row_sums

def max_absolute_row_sum(arr):
    # Get the list of absolute row sums, then return the maximum
    absolute_sums = get_absolute_row_sums(arr)
    return max(absolute_sums) if absolute_sums else 0  # Handle empty array edge case

Testing with Your Sample Input #

Using your test array [[3, -1, 4, 0], [5, 9, -2, 6], [5, 3, 7, -8]]:

test_array = [[3, -1, 4, 0], [5, 9, -2, 6], [5, 3, 7, -8]]
print(max_absolute_row_sum(test_array))  # Output: 23

This gives exactly the result you expected: max(3+1+4+0, 5+9+2+6, 5+3+7+8) = max(8,22,23) = 23.

Key Note #

The core change here is trivial but critical: wrapping each element in the absolute value function before adding it to the row sum. Your existing code for iterating rows and collecting sums doesn't need a full rewrite—just that one small adjustment to how you process individual elements.

内容的提问来源于stack exchange，提问作者Babz