Algorithm Challenges

answers.js

// #1 

String.prototype.repeatify = function(num) {
  var repeated_str = '';
  
  for (var i = 0; i < num; i++) {
    repeated_str = repeated_str + this;
  }
  
  return repeated_str;
}

'matt'.repeatify(3);


// #2 

function isPrime(num) {
  var counter = 2;
  while(counter < num) {
    if (num % counter === 0){
      return false;
    }
    counter++;
  }
  return true;
}

isPrime(135);


// #3 

function removeSpaces(str) {
  str = str.trim();
  if (str.indexOf('  ') !== -1) {
    str = str.replace('  ', ' ');
    removeSpaces(str);
  } else {
    console.log(str);
  }
}

removeSpaces(' This                is my   name               Bob. ');


// #4

function isPalindrome(str) {
  var str2 = str.split('').reverse().join('');
  return str === str2 ? true : false;
}


function isPalindrome(str) {
  while (str.length > 0) {
    if (str[0] === str[str.length - 1]) {
      str = str.slice(1, str.length -1);
    } else {
      return false;
    }
  }
  return true; 
}


isPalindrome('madam'); // true 
isPalindrome('cookies'); // false 


// #6 


function randomNum(min, max) {
  return Math.floor(Math.random() * (max - min + 1)) + min;
}

randomNum(5, 9);

problems.js

/* 

#1 Write a function that repeats a string x number of times 

	'matt'.repeatify(3); // “mattmattmatt” 


#2 Write a function that tests if a number is prime 

	isPrime(137); // true 
	isPrime(252); // false 


#3 Remove extra spaces from this string, using a recursive strategy: 

	“ Hello, my name is Bob. “ 


#4 Create a Palindrome function (word is same if reversed) 
	
	isPalindrome('madam'); // true 
	isPalindrome('cookies'); // false 

 
#5 Create a random number between any two variables: 

	randomNums(5, 9); // 6.3, 5.2, 8.9… 


#6 Create a ‘slug’ from any Given title: 
   "Hello My Name is Bob" → hello-my-name-is-bob 
   "Why do you like slugs!!!" → why-do-you-like-slugs 

   createSlug(“Hello My Name is Bob”); 


*/