Sliding Window — Dynamic / Variable Size

Key Signals & Indicators

• Target subrange width is unknown or variable
• Problem mentions maximum, minimum, or target criteria (e.g. sum = X)
• Window elements can be checked dynamically

// C++ Variable Sliding Window Template
#include <vector>

int variableSlidingWindow(const std::vector<int>& arr, int target) {
    int left = 0, currentSum = 0, minLength = 1e9;
    
    for (int right = 0; right < arr.size(); ++right) {
        currentSum += arr[right]; // Expand window
        
        // Shrink window while constraint is met
        while (currentSum >= target) {
            minLength = std::min(minLength, right - left + 1);
            currentSum -= arr[left];
            left++;
        }
    }
    return minLength == 1e9 ? 0 : minLength;
}