3/19 leetcode 문제 풀이

사전 학습!

Set 객체는 자료형에 관계 없이 원시값과 객체 참조 모두 유일한 값을 저장할 수 있다.

var set = Set();

set.add(1); // Set {1}

set.has(1); // true

set.delete(1); // 1 delete

연결 리스트정리
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#141

참고: 승지니어

var hasCycle = function(head) {

let walker = head;
let runner = head;
    
while(runner !=null){
    runner = runner.next;
    if(runner!=null){
        runner = runner.next;
        walker = walker.next;
        if(runner == walker) break;
        }else break;
    }
    if(runner==null) return false;
    else return true;

};

#155

참고: 승지니어 & https://leetcode.com/problems/min-stack/discuss/204269/javascript

/**

• initialize your data structure here.
  */
  var MinStack = function() {
  this.stack= [];
  };

/**

• @param {number} val
• @return {void}
  */
  MinStack.prototype.push = function(val) {
  let min = this.stack.length === 0? val: this.stack[this.stack.length -1].min;
  this.stack.push({val:val, min: Math.min(min,val)});
  };

/**

• @return {void}
  */
  MinStack.prototype.pop = function() {
  if(this.stack.length > 0){
  this.stack.pop();
  }
  

};

/**

• @return {number}
  */
  MinStack.prototype.top = function() {
  if(this.stack.length > 0){
  return this.stack[this.stack.length-1].val;
  }
  };

/**

• @return {number}
  */
  MinStack.prototype.getMin = function() {
  if(this.stack.length>0){
  return this.stack[this.stack.length-1].min;
  }
  };

/**

• Your MinStack object will be instantiated and called as such:
• var obj = new MinStack()
• obj.push(val)
• obj.pop()
• var param_3 = obj.top()
• var param_4 = obj.getMin()
  */

#160

참고: https://leetcode.com/problems/intersection-of-two-linked-lists/discuss/802204/Javascript-Solution%3A160

var getIntersectionNode = function(headA, headB) {

let a = headA;
let b = headB;

while(a != null && b != null){
    a = a.next;
    b = b.next;
    
    if(a === b){
        return a;
    }
    if(a === null){
        a = headB;
    }
    if(b === null){
        b = headA;
    }

}
return a ;

};

참고자료

-javascript Set() 객체
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-linked list
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