Array-DS

[문제출저][source]

문제

An array is a type of data structure that stores elements of the same type in a contiguous block of memory. In an array, , of size , each memory location has some unique index, (where ), that can be referenced as (you may also see it written as ).

Given an array, , of integers, print each element in reverse order as a single line of space-separated integers.

Note: If you’ve already solved our C++ domain’s Arrays Introduction challenge, you may want to skip this.

Input Format

The first line contains an integer, (the number of integers in ). The second line contains space-separated integers describing .

Constraints

Output Format

Print all integers in in reverse order as a single line of space-separated integers.

Sample Input 1

CopyDownload Array: arr 1 4 3 2

4 1 4 3 2 Sample Output 1

2 3 4 1

풀이코드

  • 배열의 크기 N/2만큼 반복문을 돌면서 현재위치(i)의 값과 뒤에서 i위치(n-(i+1))의 값을을 차례로 swap해줌.
  • 시간복잡도 O(N/2)
	static int[] reverseArray(int[] a) {
		for (int i = 0, n = a.length / 2; i < n; i++) {
			int tmp = a[i];
			a[i] = a[n - (i + 1)];
			a[n - (i + 1)] = tmp;

		}
		return a;
	}

source