lof_condense.js

function LoFCondense(nestedArray) {
    // Helper function to find all identical subarrays at all levels
    function findIdenticalPairs(arr) {
        let pairs = [];
        let seen = new Map();

        function traverse(currentArr, path) {
            if (!Array.isArray(currentArr)) return;

            let key = JSON.stringify(currentArr);
            if (seen.has(key)) {
                pairs.push([seen.get(key), path]);
            } else {
                seen.set(key, path);
            }

            for (let i = 0; i < currentArr.length; i++) {
                traverse(currentArr[i], path.concat(i));
            }
        }

        traverse(arr, []);
        return pairs;
    }

    // Helper function to remove a subarray at a given path
    function removeAtPath(arr, path) {
        if (path.length === 1) {
            arr.splice(path[0], 1);
        } else {
            removeAtPath(arr[path[0]], path.slice(1));
        }
    }

    // Find all identical pairs of subarrays
    let identicalPairs = findIdenticalPairs(nestedArray);

    if (identicalPairs.length === 0) {
        return nestedArray;
    }

    // Select a random pair to condense
    let randomPair = identicalPairs[Math.floor(Math.random() * identicalPairs.length)];
    let [firstPath, secondPath] = randomPair;

    // Remove the second occurrence of the identical subarray
    removeAtPath(nestedArray, secondPath);

    // Ensure the first occurrence remains
    return nestedArray;
}

{
// Test cases
let testCase1 = [[], []];
let testCase1b = [[[], []]];
let testCase2 = [[[[], []]], [[[], []]]];
let testCase3 = [[[[], []]], [[[], []]]];

console.log(JSON.stringify(LoFCondense(testCase1))); // Output: [[]]
console.log(JSON.stringify(LoFCondense(testCase1b))); // Output: [[]]
console.log(JSON.stringify(LoFCondense(testCase2))); // Possible outputs: [[[[]]], [[[], []]]], [[[[], []]]]
console.log(JSON.stringify(LoFCondense(testCase3))); // Possible outputs: [[[[]]], [[[], []]]], [[[[], []]]]
console.log(JSON.stringify(LoFCondense(testCase3))); // Possible outputs: [[[[]]], [[[], []]]], [[[[], []]]]
}