703191. Consecutive Array Elements
Here is a detailed Markdown blog post for the "Consecutive Array Elements" problem:
Consecutive Array Elements Slug: consecutive-array-elements2711 Difficulty: Easy Id: 703191 Topic Tags: Arrays, Data Structures Company Tags: None
Summary
Given an array of integers, find the maximum number of consecutive elements that have a sum equal to the given target value. For example, if the input array is [1, 2, 3, 4, 5] and the target sum is 6, the output should be 2 because there are two consecutive elements ([2, 3]) in the array that sum up to 6.
Detailed Explanation
To solve this problem, we can use a sliding window approach. We initialize two pointers, left and right, to the start of the array. We also maintain a variable current_sum to keep track of the sum of elements in the current window.
We iterate through the array, moving the right pointer to the right and updating current_sum. Whenever current_sum equals the target value, we update our maximum count of consecutive elements.
Here's a step-by-step breakdown:
- Initialize
left,right, andcurrent_sum. - Iterate through the array:
- Move
rightto the right and updatecurrent_sumby adding the element atright. - If
current_sumequals the target value, update our maximum count of consecutive elements.
- Move
- If
current_sumexceeds the target value, moveleftto the right to reduce the sum and repeat step 2.
Time complexity: O(n), where n is the length of the input array. Space complexity: O(1), as we only use a few extra variables to store our state.
Optimized Solutions
Java
public int maxConsecutive(int[] arr, int target) {
int left = 0;
int right = 0;
int currentSum = 0;
int maxCount = 0;
while (right < arr.length) {
currentSum += arr[right];
if (currentSum == target) {
maxCount = Math.max(maxCount, right - left + 1);
} else if (currentSum > target) {
currentSum -= arr[left++];
}
right++;
}
return maxCount;
}