Which of the following sorting algorithms has the lowest worst-case complexity?

Merge sort
Bubble sort
Quick sort
Selection sort

Correct answer: Merge sort

Solution

Merge sort has worst-case time complexity $O(n\log n)$. Bubble sort and selection sort are $O(n^2)$ in the worst case, and quick sort can also degrade to $O(n^2)$.

Related GATE Technical questions

Given an integer array of size $N$, we want to check whether the array is sorted in either ascending or descending order. An algorithm solves this problem by making a single pass through the array and comparing each element only with its adjacent elements. The worst-case time complexity of this algorithm is
Let $G(V,E)$ be an undirected and unweighted graph with 100 vertices. Let $d(u,v)$ denote the number of edges in a shortest path between vertices $u$ and $v$ in $V$. Let the maximum value of $d(u,v)$, for $u,v \in V$ with $u \ne v$, be 30. Let $T$ be any breadth-first-search tree of $G$. Which ONE of the given options is CORRECT for every such graph $G$?
Consider the following segment of C code: ```c int j, n; j = 1; while (j <= n) j = j * 2; ``` The number of comparisons made in the execution of the loop for any $n>0$ is:
Let `w` be the minimum weight among all edge weights in an undirected connected graph. Let `e` be a specific edge of weight `w`. Which of the following is false?
An array of `n` numbers is given, where `n` is even. The maximum as well as the minimum of these `n` numbers needs to be determined. Which of the following is true about the number of comparisons needed?
Consider the following C code segment: ```c int IsPrime(n) { int i, n; for (i = 2; i <= sqrt(n); i++) if (n % i == 0) { printf("Not Prime\n"); return 0; } return 1; } ``` Let `T(n)` denote the number of times the `for` loop is executed by the program on input `n`. Which of the following is true?

⚔️ Practice GATE Technical free + battle 1v1 →