[Java] 자바 등차수열, 피보나치 수열

> 등차수열

package days14;

public class Ex02_02 {

	public static void main(String[] args) {
		//등차수열
		//1+2+4+7+11+16+22+29+37+46+56+67+79+92+=469
		int sum=0, out=1, inc=0;
		
		while ((out += inc++) <= 100) {
			System.out.printf("%d+", out);
			sum += out;
		}
		System.out.printf("\b=%d\n",sum);
		
	}//main

}//class

> 피보나치 수열

package days14;

public class Ex03 {
	
	public static void main(String[] args) {
		// 피보나치 수열
		// 1 1 2 3 5 8 13 21 34 55 ...
		
		// 1+1 이랑 합2 할당하고 시작
		int f = 1, s = 1, t;
		System.out.printf("%d+%d+",f,s);
		
		int sum = f + s;
		int cnt = 2;
		
		while (cnt < 15) {
			t = f + s;
			System.out.printf("%d+",t);
			sum += t;
			cnt++;
			f = s;
			s = t;
		}
		System.out.printf("\b=%d\n",sum);
		
		
		
		/*
		int num1 = 0, num2 = 1, num3, sum = 0, term = 0;
		
		while (term < 15) {
			sum += num2;
			System.out.printf("%d+",num2);
			num3 = num1;
			num1 = num2;
			num2 = num1+num3;
			term++;
		}
		
		System.out.printf("\b=%d\n",sum);
		*/
		
		
	}//main
}//class

package days14;

public class Ex03_02 {
	
	public static void main(String[] args) {
		// 피보나치 수열
		// 1 1 2 3 5 8 13 21 34 55 ...
		
		// [1][1][2][3][5][8][13] ...
		int [] m = new int[15];
		m[1]=m[0]=1;
		
		for (int i = 2; i < m.length; i++) {
			m[i] = m[i-1] + m[i-2];
		}
		
		int sum = 0;
		for (int i = 0; i < m.length; i++) {
			System.out.printf("%d+", m[i]);
			sum += m[i];
		}
		System.out.printf("\b=%d\n", sum);
		
		
		
		
		/*
		int num1 = 0, num2 = 1, num3, sum = 0, term = 0;
		
		while (term < 15) {
			sum += num2;
			System.out.printf("%d+",num2);
			num3 = num1;
			num1 = num2;
			num2 = num1+num3;
			term++;
		}
		
		System.out.printf("\b=%d\n",sum);
		*/
		
		
	}//main
}//class