Java program is not giving the required output

Question

The question is to print the following series:

(a+(2^0)*b), ((a+(2^0)*b)+(a+(2^1)*b)), ((a+(2^0)*b)+(a+(2^1)*b)+(a+(2^2)*b)...+(a+(2^(n-1))*b))

The values of a,b,n and t are enterred by the user. 't' denotes the number of series that the user wants to calculate. For eg, if t=2, then the user can give two separate inputs of a,b and n and obtain two different series.

if t=2  
a=0,b=2,n=10

and for second series-

a=5,b=3,n=5

Output should be:

2 6 14 30 62 126 254 510 1022 2046  (1st series)  
8 14 26 50 98                       (2nd series) 

The program below is not showing the required output. Can someone please point out the mistakes?

import java.io.*;  

class Solution{  

    public static void main(String []argh){  

        Scanner in = new Scanner(System.in);  

        int t=in.nextInt();  

        int s=0;  

        for(int i=0;i<t;i++){  

            int  a  =  in.nextInt();    

            int  b  =  in.nextInt(); 

            int n = in.nextInt();

            for(int j=0;j<n;j++)  
            {  
                s = s+(a+(2^j)*b);  
                System.out.print(s+" ");  
            }  
        }  
        in.close();  
    }  

}  

Answer 1

In your second inner loop your variable j is never updated (you are using i instead). Your problem may come from here.

Answer 2

在第二个循环中，它应该是j，而不是我喜欢的-> for(int j=0;j<n;j++)

Answer 3

j instead of i . And use java.lang.Math.pow;

Also u have typo in String []argh => String[] args ;

And i think int s should be double s

import java.io.*;
import java.lang.*;  

    class Solution{  

        public static void main(String[] args){  

            Scanner in = new Scanner(System.in);  

            int t=in.nextInt();  

            double s=0;  

            for(int i=0;i<t;i++){  

                int  a  =  in.nextInt();    

                int  b  =  in.nextInt(); 

                int n = in.nextInt();

                for(int j=0 ; j<n ; i++)  
                {  
                    s = s+(a+(java.lang.Math.pow(2, j))*b);  
                    System.out.print(s+" ");  
                }  
            }  
            in.close();  
        }  

    }  

Answer 4

^ doesn't mean power in java. ^ means bitwise XOR. Use java.lang.Math.pow method instead.

Answer 5

内循环完成后，您应该使s = 0，系列才能重新开始