Algorithm/BOJ
BOJ_2193_이친수_java
owoowo
2022. 12. 22. 11:51
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코드
/**
백준 2103번 이친수
실버 3
*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
public class BOJ_2193_이친수 {
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer st = new StringTokenizer(br.readLine());
int N = Integer.parseInt(st.nextToken());
long ans = solution(N);
System.out.println(ans);
}
private static long solution(int N){
if (N == 0) return 0;
else if(N == 1) return 1;
else if(N == 2) return 1;
long before = 1;
long after = 2;
long fibo = 2;
for(int i = 3; i <N; i++){
fibo = before + after;
before = after;
after = fibo;
}
return fibo;
}
}