Merge Sort

public class Main {
    public static int[] src;
    public static int[] tmp;
 
    public static void main(String[] args) {
        src = new int[] { 1, 8, 5, 4, 2, 3, 7, 6 };
        tmp = new int[src.length];
        printArray(src);
        mergeSort(0, src.length - 1);
        printArray(src);
    }
 
    public static void mergeSort(int start, int end) {
        if (start < end) {
            int mid = (start + end) / 2;
            mergeSort(start, mid);
            mergeSort(mid + 1, end);
            int p = start;
            int q = mid + 1;
            int idx = p;
            while (p <= mid || q <= end) {
                if (q > end || (p <= mid && src[p] <= src[q])) {
                    tmp[idx++] = src[p++];
                } else {
                    tmp[idx++] = src[q++];
                }
            }
            for (int i = start; i <= end; i++) {
                src[i] = tmp[i];
            }
        }
    }
 
    public static void printArray(int[] a) {
        for (int i = 0; i < a.length; i++)
            System.out.print(a[i] + " ");
        System.out.println();
    }
 
}
 

 

 

참고 사이트 : https://yunmap.tistory.com/entry/%EC%95%8C%EA%B3%A0%EB%A6%AC%EC%A6%98-Java%EB%A1%9C-%EA%B5%AC%ED%98%84%ED%95%98%EB%8A%94-%EC%89%AC%EC%9A%B4-Merge-Sort-%EB%B3%91%ED%95%A9-%EC%A0%95%EB%A0%AC-%ED%95%A9%EB%B3%91-%EC%A0%95%EB%A0%AC