牛牛准备继续进阶,计算更难的数列
输入一个整数n,计算 1+1/(1-3)+1/(1-3+5)+...+1/(1-3+5-...((-1)^(n-1))*(2n-1))的值
import java.util.Scanner; // 注意类名必须为 Main, 不要有任何 package xxx 信息 public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); while (in.hasNextInt()) { // 注意 while 处理多个 case int a = in.nextInt(); double sum =0.0; double den = 0.0; int f = 1; for(double i =1.0;i<=a ;i++) { den+=f*(2*i-1); sum+= 1/den; f=-f; } System.out.println(String.format("%.3f",sum)); } } }
import java.util.Scanner; // 注意类名必须为 Main, 不要有任何 package xxx 信息 public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); int n=in.nextInt(); double a=0.0; double b=0.0; for(int i=1;i<=n;i++){ b=b+Math.pow(-1,i-1)*(2*i-1); a=a+1.0/b; } System.out.printf("%.3f",a); } }
import java.util.Scanner; public class Main{ public static void main(String[] args){ Scanner sc=new Scanner(System.in); int n=sc.nextInt(); float count=0; for(int i=1;i<=n;i++){ count+=1/cal(i); } System.out.printf("%.3f",count); } public static float cal(int x){ float count=0; for(int i=1;i<=x;i++){ count+=Math.pow(-1,i-1)*(2*i-1); } return count; } }
import java.util.*; public class Main { public static void main(String[] arg) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); double fen = 0; double sum1 = 0; double sum2 = 0; for (int i = 1; i <= n; i++) { fen = 1 / (double)i; if (i % 2 != 0) { sum1 += fen; } else { sum2 += fen; } } System.out.printf("%.3f", (sum1 - sum2)); } }
import java.util.*; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); while(scanner.hasNext()){ double num = scanner.nextDouble(); double sum = 0.0; for(int i = 1;i <= num;i++){ if(i % 2 == 0){ sum = sum - (double)(1.0 / i); }else{ sum = sum + (double)(1.0 / i); } } System.out.println(String.format("%.3f",sum)); } } }
import java.util.*; public class Main{ public static void main(String love[]){ Scanner input=new Scanner(System.in); int n=input.nextInt(); double sum=0; for(int i=1;i<=n;i++){ if(i%2==0){ sum-=(double) 1/i; } else{ sum+=(double) 1/i; } } System.out.printf("%.3f",sum); input.close(); } }