5.mergeSort - Javascript

5.mergeSort - Javascript

const arr = [5,1,3,2,1,4]


function merge(left, right) {
    let result = [];
    while (left.length && right.length) { // ___.length가 true일 때 === 배열 안에 값이 남아있을 때
        if (left[0] <= right[0]) { 
        result.push(left.shift()); // shift() 메서드는 배열에서 첫 번째 요소를 제거하고, 제거된 요소를 반환합니다.
        } else {
        result.push(right.shift()); 
        }
    }
    while (left.length) result.push(left.shift()); 
    while (right.length) result.push(right.shift());
    return result;
};


const mergeSort = function(array) {
    if (array.length < 2) return array; 
    let pivot = Math.floor(array.length / 2); //쪼개기
    let left = array.slice(0, pivot); 
    let right = array.slice(pivot, array.length); 
    return merge(mergeSort(left), mergeSort(right)); // 재귀
  }



console.log(mergeSort(arr));