My Solutions and answers to exercise questions in "Introduction to Algorithms" 3rd Edition

For Datastructures/Algorithms

1. Short summary of what is is
2. Why you use it
3. Pros
4. Cons
5. Example (Code snippet)

Description: A list

1. Allows Random Access
2. Can be sorted
3. Mutable
4. Easily convert to string

1. Insertion and Deletion are costly because the array must reindexed

var removeElement = function(nums, val) {
    //Splice out value
    for (let i = nums.length; i >= 0; i--) {
        if (nums[i] === val) {
            nums.splice(i, 1);
        }
    }
    return nums.length;
};

Description: Object used to store the frequency of items

1. Constant time loop up if you have the key vs array.includes
2. Can use array methods on Object.keys()
3. Store, acces, and delete data
4. Caches

1. Hashed collisions - Two separate values could create the same hash value.

var intersect = function(nums1, nums2) {
    let hash = {};
    for (let num of nums1) {
        hash[num] = (hash[num] || 0) + 1;
    }
    let results = [];
    for (let num of nums2) {
        if (hash[num]) {
            hash[num]--;
            results.push(num);
        }
    }
    return results;
};