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170 Two Sum Iii

/**
 * 
 * Ashish Patel
 * e: ashishsushilPatel@gmail.com
 * w: https://ashish.me
 *
 */

/* 
 * Design and implement a TwoSum class. It should support the following operations: add and find.
 * 
 * add - Add the number to an internal data structure.
 * find - Find if there exists any pair of numbers which sum is equal to the value.
 * 
 * Example 1:
 * 
 * add(1); add(3); add(5);
 * find(4) -> true
 * find(7) -> false
 * 
 * Example 2:
 * 
 * add(3); add(1); add(2);
 * find(3) -> true
 * find(6) -> false 
*/

const TwoSum = function() {
  this.map = {}
}

TwoSum.prototype.add = function(number) {
  if(this.map[number]){
    this.map[number] += 1
  } else {
    this.map[number] = 1
  }
}

TwoSum.prototype.find = function(value){
  for (const key in this.map) {
    const currentNumber = key - 0
    const complement = value - currentNumber
    if (this.map[complement] && (currentNumber !== complement || this.map[complement] > 1)) {
      return true      
    }
  }
  return false
}

test('two Sum III', () => {
  const twoSum = new TwoSum()
  twoSum.add(3)
  twoSum.add(1)
  twoSum.add(2)
  expect(twoSum.find(6)).toEqual(false)
});

Created 2020-04-08T22:40:46+00:00 · Edit