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Articles on Trending Technologies
Technical articles with clear explanations and examples
Largest BST Subtree in C++
Suppose we have a binary tree; we have to find the largest subtree of it where largest means subtree with largest number of nodes in it.So, if the input is like, then the output will be 3, as the Largest BST Subtree, in this case, is the highlighted one.To solve this, we will follow these steps −Define one structure called data, there will be four values, size, maxVal, minVal, and ok, the ok can hold only true/false valuessolve(TreeNode * node)if node is null, then &miuns;return Data by initializing (0, infinity, -infinity, true)left := solve(left of node)left := solve(right of node)Define ...
Read MoreCount numbers in range that are divisible by all of its non-zero digits in C++
We are provided two numbers START and END to define a range of numbers.The goal is to find all the numbers in the range [START, END] that are divisible by all of its non-zero digits . We will do this by traversing numbers from START to END and for each number we will check if the number is divisible by all non-zero digits using a while loop. If yes increment count.Let’s understand with examples.Input START=10 END=20Output Numbers that are divisible by all its non-zero digits: 14Explanation Numbers 10, 11, 12, 15, 20 are divisible by all their non-zero digits.Input START=100 END=200Output Numbers that are divisible ...
Read MoreAndroid Unlock Patterns in C++
Suppose we have an Android 3x3 key lock screen and two integers m and n, the values of m and n are in range 1 ≤ m ≤ n ≤ 9, We have to count the total number of unlock patterns of the Android lock screen, which consist of minimum of m keys and maximum n keys.The rule is like, each pattern must connect at least m keys and at most n keys. All the keys must be unique. If there is a line connecting two consecutive keys in the pattern passes through any other keys, the other keys must ...
Read MoreHow to add a column in an R data frame with consecutive numbers?
Addition of a column with consecutive might have different objectives such as getting the sequence of numbers, representing serial numbers, representing ids, identification of each row, or a variable. We can use the sequence starting from any number up to the number of rows if we know the number of rows for this purpose.Example1Consider the below data frame:> x1 x2 df1 df1Output x1 x2 1 6.137898 5.203712 2 5.283467 5.057344 3 5.873749 4.907388 4 7.628762 5.012650 5 4.134700 4.988379 6 5.340686 4.684900 7 5.126999 4.821752 8 3.722762 4.974044 9 4.097969 ...
Read MoreCount numbers with difference between number and its digit sum greater than specific value in C++
We are provided two numbers N which defines a range [1, N] and D which is a difference.The goal is to find all the numbers in the range [1, N] such that the [ number - (sum of its digits) ] > D. We will do this by traversing numbers from 1 to N and for each number we will calculate its digit sum using a while loop. Check if the number and calculated digit sum has a difference more than D.Let’s understand with examples.Input N=15 D=5Output Numbers such that difference b/w no. and its digit sum greater than value D: 6Explanation Numbers ...
Read MoreWhy scale_fill_manual does not fill the bar with colors created by using ggplot2 in R?
We can manually fill the color of bars in a bar plot which is created by using ggplot2 but for this we would be needing color aesthetics already used for the bars. That means we need to use filling of bars inside aes of ggplot2 and then the colors can be mentioned inside the scale_fill_manual function.ExampleConsider the below data frame:> x count df dfOutputx count 1 A 321 2 B 324 3 C 320 4 D 328Loading ggplot2 package and creating bar plot:Example> library(ggplot2) > ggplot(df, aes(x, count))+geom_bar(stat="identity")Output:Creating the bar plot by using scale_fill_manual:Example> ggplot(df, aes(x, count))+geom_bar(stat="identity")+scale_fill_manual(values=c("blue", "green", "grey", "yellow"))OutputThis ...
Read MoreCount of common multiples of two numbers in a range in C++
We are given two numbers A and B. Also provided two numbers START and END to define a range of numbers. The Ath tile has paint white and Bth tile has paint black. If the tile is painted both black and white then it turns grey. The goal is to find the total number of grey tiles .We will do this by traversing numbers from START to END and for each number we will check if the number is multiple of both A and B. If yes increment count.Let’s understand with examples.Input START=10 END=20 A=3 B=6Output Common multiples of A and B ...
Read MoreHow to create a covariance matrix in R?
To create a covariance matrix, we first need to find the correlation matrix and a vector of standard deviations is also required. The correlation matrix can be found by using cor function with matrix object. For example, if we have matrix M then the correlation matrix can be found as cor(M). Now we can use this matrix to find the covariance matrix but we should make sure that we have the vector of standard deviations.Example1> M1 M1Output [, 1] [, 2] [, 3] ...
Read MoreHow to find the residual of a glm model in R?
In a linear model, a residual is the difference between the observed value and the fitted value and it is not different for a general linear model. The difference between linear model and the general linear model is that we use a probability distribution to create a general linear model. If we want to find the residual for a general linear model then resid function can be used just like it is used with the linear model.Example1Consider the below data frame:> x1 y1 df1 df1Output x1 y1 1 4 2 2 3 3 3 5 3 4 4 2 5 ...
Read MoreCount of numbers from range[L, R] whose sum of digits is Y in C++
We are provided two numbers START and END to define a range of numbers.The goal is to find all the numbers in the range [START, END] which have sum of digits equal to a given number Y.We will do this by traversing numbers from START to END and for each number we will count the sum of its digit using a while loop. If this sum is equal to Y, increment count.Let’s understand with examples.Input START=10 END=20 Y=4Output Numbers such that digit sum is equal to Y: 1Explanation Number 13 has digit sum equal to 4.Input START=10 END=50 Y=5Output Numbers such that digit sum is ...
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