DP / 백준 2193 이친수

 

문제 접근

dp[i] = dp[i-2] + dp[i-1] 점화식 도출

풀이

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class S2193 {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        int N = Integer.parseInt(br.readLine());
        long[] dp = new long[91];

        dp[1] = 1;
        dp[2] = 1;

        for (int i = 3; i <= N; i++) {
            dp[i] = dp[i - 2] + dp[i - 1];
        }

        System.out.println(dp[N]);
    }
}