Interview

gistfile1.js

// Source http://www.thatjsdude.com/interview/js1.html

/*
|--------------------------------------------------------------------------
|  Log p()
|--------------------------------------------------------------------------
|
*/

var p = function(a) {
  console.log(a);
};

/*
|--------------------------------------------------------------------------
|  Spacify
|--------------------------------------------------------------------------
|
*/

function spacify(args) {
  return args.split("").join(" ");
}

String.prototype.spacify = function(args) {
  return this.split("").join(" ");
};

// p("Hello".spacify());

/*
|--------------------------------------------------------------------------
|  Check Prime
|--------------------------------------------------------------------------
|
*/

function isPrime(args) {
  var d = 2;
  while(args > d) {
    if(args % d++ === 0) return false;
  }
  return true;
}

// p(isPrime(7));

/*
|--------------------------------------------------------------------------
|  Fibonacci
|--------------------------------------------------------------------------
|
*/

function fibonacci(args) {
  var score = 0,
      val = 1;
  while(args--) {
    score += val;
    val = score - val; 
  }
  return score;
}

// p(fibonacci(6));

/*
|--------------------------------------------------------------------------
|  Greatest Common Divisor
|--------------------------------------------------------------------------
|
*/

function greatestDivisor(arg1, arg2) {
  var divisor = 2,
      score;

  while(arg1 >= divisor && arg2 >= divisor) {
    if(arg1 % divisor === 0 && arg2 % divisor === 0) {
      score = divisor;
    }
    divisor++;
  }
  return score;
}

// p(divisor(14,21));

/*
|--------------------------------------------------------------------------
|  Duplicate
|--------------------------------------------------------------------------
|
*/

// Array.prototype.contains = function(args) {
//   var len = this.length;
//   while(len--) if(this[len] == args) return true;
//   return false;
// }

function duplicate(args) {
  var score=[],
      temps=[],
      len = args.length;

  for(i=0; i<len; i++) {
    val = args[i];

    if(temps[val] !== false) {
      score.push(val);
      temps[val] = false;
    }
  }
  return score;
}

// p(duplicate([1,1,2,3,4,4,4,5,1]));

/*
|--------------------------------------------------------------------------
|  Merge array
|--------------------------------------------------------------------------
|
*/

function mergeArr(arg1, arg2) {
  return arg1.concat(arg2).sort(function(a,b){ 
    return a - b;
  });
}

// p(mergeArr([2,5,29], [1,3,7,12]));

/*
|--------------------------------------------------------------------------
|  String Reverse
|--------------------------------------------------------------------------
|
*/

function reverse(arg) {
  if(arg && typeof arg === 'string') {
    return arg.split("").reverse().join("");    
  }
}

// p(reverse("Siemka"));

/*
|--------------------------------------------------------------------------
|  Reverese in place
|--------------------------------------------------------------------------
|
*/

function reverseInPlace(args){
  var score = [];
  args = args.split(" ");

  for(i=0; i<args.length; i++) {
    score.push(args[i].split("").reverse().join(""));
  }
  return score.join(" ");
}

// p(reverseInPlace('I am the good boy'));

/*
|--------------------------------------------------------------------------
|  First non repeating char
|--------------------------------------------------------------------------
|
*/

function firstNonRepeatingChar(arg) {
  var val,
      len = arg.length,
      arr = [];

  for(i=0; i<len; i++) {
    val = arg[i];
    if(arr[val]) {
      arr[val]++;
    } else {
      arr[val] = 1;
    }
  }

  for(var j in arr) {
    if(arr[j] == 1) return j;
  }
}

// p(firstNonRepeatingChar("The Javascript"));

/*
|--------------------------------------------------------------------------
|  Remove duplicate char
|--------------------------------------------------------------------------
|
*/

function removeDuplicateChar(arg) {
  var val,
      len = arg.length,
      arr = [],
      score = [];

  for(i=0; i<len; i++) {
    val = arg[i];
    if(arr[val]) {
      arr[val]++;
    } else {
      arr[val] = 1;
    }
  }

  for(var j in arr) {
    if(arr[j] == 1) {
      score.push(j);
    }
  }
  return score.join("");
}

// p(removeDuplicateChar("Learn more javascript dude"));

/*
|--------------------------------------------------------------------------
|  Check palindrome
|--------------------------------------------------------------------------
|
*/

function isPalindrome(arg) {
  s1 = arg.split("").reverse().join("");
  return s1 === arg;
}

// p(isPalindrome("madam"));


/*
|--------------------------------------------------------------------------
|  Missing number
|--------------------------------------------------------------------------
|
*/

function missingNumber(arg) {
  var val=0,
      max=0,
      len = arg.length;

  for(i=0; i<len+2; i++) {
    max += i;
    if(i < len)
      val += arg[i];
  }
  return max - val;
}

// p(missingNumber([5,2,6,1,3]));

/*
|--------------------------------------------------------------------------
|  Largest Sum
|--------------------------------------------------------------------------
|
*/

function largestSum(arg) {
  var len = arg.length;

  arg = arg.sort(function(a,b){ return a-b; });
  return arg[len-1] + arg[len-2];
}

// p(largestSum([6,4,3,2,1,7]));