Greedy Algorithms

Master Greedy Algorithm with 7 Basic Problems [Solution + Code included]

In this article at OpenGenus, we will discuss the about how to master greedy algorithms by solving 7 basic problems using greedy algorithmic ideas.

Greedy Algorithms

Assign Cookies problem

Assign cookies problem is a popular coding interview question which is mostly solved using greedy algorithm. Here, you will be given a list of children/siblings and a list of cookies with their sizes.

Algorithms

Greedy Algorithm vs Dynamic programming

In this article, we will discuss greedy methods vs dynamic programming. Both of them are used for optimization of a given problem. Optimization of a problem is finding the best solution from a set of solutions.

Greedy Algorithms

Fitting Shelves Problem [Greedy Algorithm]

In this article, we will understand what fitting shelves problem is and will see a greedy approach algorithm of solving this problem.

List of Mathematical Algorithms

Egyptian Fraction Problem [Greedy Algorithm]

In this article, we will explore the fascinating concept of Egyptian Fractions and will learn what they are and will also see an example of how they can be solved using greedy algorithm techniques.

Algorithms

Fractional Knapsack problem

In this article, we have explored fractional knapsack problem with examples. We have covered multiple approaches to solve this.

Algorithms

Jump Game II: Minimum number of jumps to last index

In this post, we will explore various ways to solve the minimum number of jumps to last index (Jump Game II) problem. In this, we will use ideas of Dynamic Programming and Greedy Algorithm.

Algorithms

Remove K digits to make smallest number

We will be solving the problem of removing K digits from a given number to form the smallest number possible without changing the order of the original number. We will use the idea of Monotonic Stack

Algorithms

Scheduling tasks to Minimize Lateness

In this article, we have explored techniques to schedule tasks (with a deadline and time required to complete it) in a way to decrease the time lag in finish time and deadline of the chosen request (i.e., lateness).

Algorithms

Smallest Missing Positive Integer

The problem is to find out the smallest missing positive integer given an unsorted integer array. We can solve this problem in linear time O(N) and in constant time O(1) using a greedy approach with hash map.

Algorithms

Find Maximum Perimeter of a Triangle

Given an array of integers, find which three elements form a non-degenerate triangle such that the triangle has maximum perimeter. This can be done using a Greedy algorithm by sorting the array of integers.

Algorithms

Make N numbers equal by incrementing N-1 numbers

Given an array, find the minimum number of operations to make all the array elements equal. The operation includes incrementing all but one element of the array by 1.

Algorithms

Split a number into K unique parts such that their GCD is maximum

The problem is to split a number N into K unique parts such that the sum of the parts is equal to N and the greatest common divisor of the K parts is maximum. This can be solved in O(N^1/2) time complexity using a greedy approach.

Algorithms

Largest Palindromic Number by Rearranging Digits

Given N (very large), we need to find the largest palindromic number by rearranging digits. If it is not possible to print the largest palindromic number from N then, print "Palindrome not found".

Algorithms

Smallest Palindrome greater than N using the same set of digits

We are given an number and we have to find the smallest pallindrome number greater than N which can be formed by using the same set of digits as in N. We have solved this using a Greedy approach in linear time.

Algorithms

Closest string such that no two consecutive characters are same

We are given a string and we have to find the closest string such that no two characters in the string are same. This problem can be solved using a simple greedy approach which will take linear time O(N) and constant space O(1).

Algorithms

Minimum number of Fibonacci terms with sum equal to a given number N

Given a number N, we need to find the minimum number of fibonacci numbers required that sums up to a given number N. Note a fibonacci number can be repeated

Algorithms

Find the largest number with given number of digits and sum of digits

In this problem, we need to find the largest number with a given number of digits N and given sum of digits say M. We will use a greedy algorithm to solve this is O(N) time complexity.

Algorithms

Find the smallest number with given number of digits and sum of digits

We are given two positive integers M and N. The task is to find the smallest number that has length M (number of digits) and sum of digits as N. We will solve this using a greedy approach in O(M)

Algorithms

Split N into maximum composite numbers

Given a number N, the problem is to count the maximum number of composite numbers that sum up to N. We solve this using a greedy algorithm in constant time

Algorithms

Maximize the sum of array[i]*i

Given an array of N integer, we have to maximize the sum of arr[i] * i. Brute force approach will take O(N*N!) time while greedy algorithm will take O(N log N) time

Algorithms

The smallest subset with sum greater than sum of all other elements

In this article, we explored a greedy algorithm to find the smallest subset with sum greater than sum of all other elements in O(N log N) time complexity

Algorithms

Find Minimum sum of product of two arrays

In this article, we explored a greedy algorithm to find the minimum sum of product of two arrays in O(N log N) time whereas the brute force approach takes O(N!^2) time

Algorithms

Find the Largest Cube formed by deleting minimum number of digits from a number

In this article, we find the Largest Cube formed by deleting minimum number of digits from a number using a greedy algorithm which takes O(N^(1/3)log(N)log(N)) time

Algorithms

Find the Largest lexicographic array with at most K consecutive swaps

For a given array, find the largest lexicographic array which can be obtained from it after performing at most K consecutive swaps.