If you want to learn more about the IAS computer, check this post. The problem: Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, … By considering […]
The IAS Machine was the first electronic computer built at the Institute of Advanced Studies (hence the name) at Princeton. The leader of the project was John Von Neumann, who was also a consultant at the ENIAC project (the first general purpose electronic computer). The IAS project was quite important because it was one of […]
Here’s the problem: —– 2^15 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26. What is the sum of the digits of the number 2^1000? —– My Solution Here’s the solution implementing the large number as an array of digits: #include <stdio.h> #define MAX […]
Below the second problem of the qualification round of the Facebook Hacker Cup 2013: ——– Your friend John uses a lot of emoticons when you talk to him on Messenger. In addition to being a person who likes to express himself through emoticons, he hates unbalanced parenthesis so much that it makes him go 🙁 […]
The problem: ——- Starting in the top left corner of a 22 grid, there are 6 routes (without backtracking) to the bottom right corner. How many routes are there through a 2020 grid? ——- My Solution #include <stdio.h> int main(){ int i,j,x,y; long long int mat[21][21]; i=0; for (j=0;j<21;j++) mat[i][j]=1; j=0; for (i=0;i<21;i++) mat[i][j]=1; for […]
This weekend the qualification round of the Facebook Hacker Cup 2013 took place. Below you’ll find the first problem: ———- When John was a little kid he didn’t have much to do. There was no internet, no Facebook, and no programs to hack on. So he did the only thing he could… he evaluated the […]
Here’s the problem: ———— The following iterative sequence is defined for the set of positive integers: n n/2 (n is even) n 3n + 1 (n is odd) Using the rule above and starting with 13, we generate the following sequence: 13 40 20 10 5 16 8 4 2 1 It can be seen […]
He’s an interesting albeit relatively easy problem from CodeChef.com: ———- Reverse Polish Notation (RPN) is a mathematical notation where every operator follows all of its operands. For instance, to add three and four, one would write “3 4 +” rather than “3 + 4”. If there are multiple operations, the operator is given immediately after […]
Here’s the problem:
Work out the first ten digits of the sum of the following one-hundred 50-digit numbers.
Still practicing for Facebook Hacker Cup 2013. The problem below is a classic, although I wouldn’t necessarily classify it as “easy” as the guys from CodeChef did. Anyway here you go: ———- Let’s consider a triangle of numbers in which a number appears in the first line, two numbers appear in the second line, three […]