CATEGORY: HARD Problem Design a stack-like data structure to push elements to the stack and pop the most frequent element from the stack. Implement the FreqStack class: FreqStack() constructs an empty frequency stack. void push(int val) pushes an integer val onto the top of the stack. int pop() removes and returns the most frequent element in the stack. If there is a …
CATEGORY: MEDIUM Problem The string “PAYPALISHIRING” is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)
1 2 3 | P A H N A P L S I I G Y I R |
And then read line by line: “PAYPALISHIRING” Write the code that will take a string and make this conversion given a number …
Highly divisible triangular number The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28. The first ten terms would be: 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, … Let …
Project Euler 12: Highly divisible triangular number Read More »
Largest product in a grid problem of project Euler with detailed explaination and code in Java and Python.
Category: Medium Problem A robot is located at the top-left corner of a m x n grid (marked ‘Start’ in the diagram below). The robot can only move either down or right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked ‘Finish’ in the diagram below). How many …
Problem A Pythagorean triplet is a set of three natural numbers, a < b < c , for which,a2 + b2 = c2 For example, 32 + 42 = 9 + 16 = 25 = 52. There exists exactly one Pythagorean triplet for which a+b+c = 1000.Find the product abc. Official Problem Solution Approach In this problem of Special Pythagorean triplet, we …
Summation of primes The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17. Find the sum of all the primes below two million. Official Problem Solution Approach In this problem of Summation of primes till 1 million, we are supposed to find the sum of all the prime …
Problem The four adjacent digits in the 1000-digit number that have the greatest product are 9 × 9 × 8 × 9 = 5832. Find the thirteen adjacent digits in the 1000-digit number that have the greatest product. What is the value of this product? Official Problem Solution Approach In this problem of the Largest …
Problem By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13. What is the 10001st prime number? Official Problem Solution Approach In this problem of the 10001st prime, we have to find the 10001st prime number. A prime number is a natural …
Problem The sum of the squares of the first ten natural numbers is, 12+22+…+102=385 The square of the sum of the first ten natural numbers is, (1+2+…+10)2=552=3025 Hence the difference between the sum of the squares of the first ten natural numbers and the square of the sum is 3025−385=2640. Find the difference between the …
