Valid Mountain Array
As a Systems Engineer at Tata Consultancy Services, I deliver exceptional software products for mobile and web platforms, using agile methodologies and robust quality maintenance. I am experienced in performance testing, automation testing, API testing, and manual testing, with various tools and technologies such as Jmeter, Azure LoadTest, Selenium, Java, OOPS, Maven, TestNG, and Postman.
I have successfully developed and executed detailed test plans, test cases, and scripts for Android and web applications, ensuring high-quality standards and user satisfaction. I have also demonstrated my proficiency in manual REST API testing with Postman, as well as in end-to-end performance and automation testing using Jmeter and selenium with Java, TestNG and Maven. Additionally, I have utilized Azure DevOps for bug tracking and issue management.
Given an array of integers arr, return true if and only if it is a valid mountain array.
Recall that arr is a mountain array if and only if:
LeetCode Problem - 941
class Solution {
public boolean validMountainArray(int[] arr) {
// Check if the array has at least three elements
if (!(arr.length >= 3)) return false;
// Flag to track if we have reached the peak
boolean flag = false;
int check = arr[0]; // Initialize the peak value to the first element
// Flags to indicate if we've seen an increase or a decrease
boolean dec = false;
boolean inc = false;
// Variable to track the previous value to check for duplicates
int preValue = -1;
for (int i = 0; i < arr.length; i++) {
// Check for duplicate values
if (preValue == arr[i]) {
return false; // If the current value equals the previous, return false
} else {
preValue = arr[i]; // Update the previous value
}
// Handle the increasing and decreasing phases of the mountain
if (!flag) {
// If we haven't reached the peak yet
if (arr[i] > check) {
check = arr[i]; // Update peak value
inc = true; // Mark that we've seen an increase
} else if (arr[i] < check) {
// We have reached the peak
check = arr[i]; // Update peak value
flag = true; // Set flag indicating we are now in the decreasing phase
// If we are at the last element, check if we have started decreasing
if (arr.length - 1 == i) {
dec = true;
}
}
} else {
// We are in the decreasing phase
if (arr[i] < check) {
check = arr[i]; // Continue to update peak value
dec = true; // Confirm we are still decreasing
} else {
return false; // If we increase during the decreasing phase, return false
}
}
}
// We must have seen both an increase and a decrease to form a valid mountain
if (!dec || !inc) {
return false;
}
return true; // Return true if it is a valid mountain array
}
}
