In Java, how to append a string more efficiently?
Use StringBuilder class. It is more efficient at what you are trying to do.
arrays
When will the worst case of Merge Sort occur?
The worst case of merge sort will be the one where merge sort will have to do maximum number of comparisons. So I will try building the worst case in bottom up manner: Suppose the array in final step after sorting is {0,1,2,3,4,5,6,7} For worst case the array before this step must be {0,2,4,6,1,3,5,7} because here left subarray={0,2,4,6} and right … Read more
Correct way of looping through C++ arrays
In C/C++ sizeof. always gives the number of bytes in the entire object, and arrays are treated as one object. Note: sizeof a pointer–to the first element of an array or to a single object–gives the size of the pointer, not the object(s) pointed to. Either way, sizeof does not give the number of elements in the array (its length). To get the … Read more
What does ** do in C language?
In C arguments are passed by values. For example if you have an integer varaible in main and the following function then if you call the function in main like this then the parameter gets the value of variable x in main. However the parameter itself occupies a different extent in memory than the argument. So any … Read more
What is a list in Bash?
I have searched for a similar question here, but surprisingly could not find any. In GNU bash, there is (a construct? a structure? a data type?) called “arrays“. Arrays are well documented in the bash documentation, so I think that I understand the basics. But suddenly, in the documentation there also comes up the term … Read more
How to convert int[] into List in Java?
There is no shortcut for converting from int[] to List<Integer> as Arrays.asList does not deal with boxing and will just create a List<int[]> which is not what you want. You have to make a utility method.
Javascript Uncaught TypeError: Cannot read property ‘0’ of undefined
The error is here: You are passing the first item of words, instead of the array. Instead, pass the array to the function: Problem solved! Here’s a breakdown of what the problem was: I’m guessing in your browser (chrome throws a different error), words[] == words[0], so when you call hasLetter(“a”,words[]);, you are actually calling hasLetter(“a”,words[0]);. So, in essence, … Read more
Calculating Standard Deviation & Variance in C++
As the other answer by horseshoe correctly suggests, you will have to use a loop to calculate variance otherwise the statement var = ((Array[n] – mean) * (Array[n] – mean)) / numPoints; will just consider a single element from the array. Just improved horseshoe’s suggested code: Your sum works fine even without using loop because … Read more
How to convert List to int[] in Java?
Unfortunately, I don’t believe there really is a better way of doing this due to the nature of Java’s handling of primitive types, boxing, arrays and generics. In particular: List<T>.toArray won’t work because there’s no conversion from Integer to int You can’t use int as a type argument for generics, so it would have to be an int-specific method (or one which used reflection to do … Read more
what does “>>>” mean in java?
The >>> operator is the unsigned right bit-shift operator in Java. It effectively divides the operand by 2 to the power of the right operand, or just 2 here. The difference between >> and >>> would only show up when shifting negative numbers. The >> operator shifts a 1 bit into the most significant bit if it was a 1, and the >>> shifts in a 0 regardless. UPDATE: Let’s average 1 and 2147483647 (Integer.MAX_VALUE). We can do the … Read more