Q10844. 쉬운 계단 수

n크기의 계단수를 더해주며 나아가는 로직.

import java.io.BufferedReader; import java.io.InputStreamReader; import java.util.StringTokenizer; public class Q10844 { static long[][] array; public static void main(String[] args) throws Exception { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(br.readLine()); int num = Integer.valueOf(st.nextToken()); array = new long[num+1][10]; for (int i = 1; i <= 9; i++) { array[1][i] = 1; } for (int i = 2; i <= num; i++) { array[i][0] = array[i-1][1]; array[i][1] = array[i-1][0] + array[i-1][2] % 1000000000; array[i][2] = array[i-1][1] + array[i-1][3] % 1000000000; array[i][3] = array[i-1][2] + array[i-1][4] % 1000000000; array[i][4] = array[i-1][3] + array[i-1][5] % 1000000000; array[i][5] = array[i-1][4] + array[i-1][6] % 1000000000; array[i][6] = array[i-1][5] + array[i-1][7] % 1000000000; array[i][7] = array[i-1][6] + array[i-1][8] % 1000000000; array[i][8] = array[i-1][7] + array[i-1][9] % 1000000000; array[i][9] = array[i-1][8]; } long result = 0; for (int i = 0; i <= 9; i++) { result += array[num][i]; result %= 1000000000; } System.out.println(result); } }