BFS or Breadth First Search is a very well-known graph traversal algorithm. The following java program performs this algorithm using adjacency list representation of graphs. Graphs may contain a cycle. To avoid processing a node twice, we used a Boolean array, name visited.

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**Algorithm in Java**. Show all postsShowing posts with label

**Algorithm in Java**. Show all posts## Sunday, December 17, 2017

## Friday, December 15, 2017

### Generate unique permutation in Java

We already saw how to generate all possible permutation in java. Today we will modify our algorithm to remove duplicate entries to keep only unique permutation.

For an example, if the given string is: 112, our program will generate:

112

121

211

For an example, if the given string is: 112, our program will generate:

112

121

211

## Thursday, November 23, 2017

### Sieve of Eratosthenes In Java

The sieve of Eratosthenes is a famous ancient algorithm to find all prime numbers up to a given limit. We are going to implement this algorithm in Java.

a) Lets we have an array of size 25.

b) First start with 2, remove all numbers which are divisible by 2.

c) Find the next number, which is 3. Remove all numbers which are divisible by 3.

d) Next survivor is 5 and we repeat the same procedure.

e) For the given limit 25, we don't need to find anymore survivor after 5, as 5 X 5 = 25. In other words, we only process up to the square root of the limit.

f) All survivor numbers in the array are Prime. We save those numbers in a separate array.

**Steps we will follow:**a) Lets we have an array of size 25.

b) First start with 2, remove all numbers which are divisible by 2.

c) Find the next number, which is 3. Remove all numbers which are divisible by 3.

d) Next survivor is 5 and we repeat the same procedure.

e) For the given limit 25, we don't need to find anymore survivor after 5, as 5 X 5 = 25. In other words, we only process up to the square root of the limit.

f) All survivor numbers in the array are Prime. We save those numbers in a separate array.

### Generate all possible permutations in Java using recursion.

In the previous example, we drew a pyramid in java without any loop. We used recursion to achieve our goal and hopefully, you got a very clear idea how recursion works. In the following example, I will show you how to print all permutations of a given string. If the given string is "1234", then all possible permutations are:

1234

1243

1324

1342

1324

1342

1423

1432

.

.

.

4321

A total number of permutations are 24. ( 4! = 24 )

1234

1243

1324

1342

1324

1342

1423

1432

.

.

.

4321

## Tuesday, November 14, 2017

### Pascal Triangle In Java

Pascal Triangle is one of the most interesting number pattern which is a triangular array of the binomial coefficients. The following example shows how to generate this triangle in Java.

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