Maximum Absolute Sum of Any Subarray

Since we are trying to find the maximum absolute sum of any subarray, and the sum of any subarray can be calculated from the difference between 2 prefix sums, we can literally just iterate through nums, find the largest prefix sum, largest, and the smallest prefix sum, smallest, and return larget-smallest.

code

class Solution {
public:
    int maxAbsoluteSum(vector<int>& nums) {
        int largest = 0;
        int smallest = 0;
        int prefix_sum = 0;
        for (int i = 0; i < nums.size(); ++i) {
            prefix_sum += nums[i];
            largest = max(largest, prefix_sum);
            smallest = min(smallest, prefix_sum);
        }
        return largest-smallest;
    }
};

complexity

• Time: O(n)
• Space: O(1)