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  1. Practice
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  4. Java Loops II
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Java Loops II

  • synhack + 3 comments

    That's good. You can simplify even further if you realize that 2^0 + 2^1 + ... + 2^j = 2^(j+1) - 1

    class Solution{
    public static void main(String []argh){
        Scanner in = new Scanner(System.in);
        int t=in.nextInt();
        StringBuilder sb = new StringBuilder();
        for(int i=0;i<t;i++){
            int a = in.nextInt();
            int b = in.nextInt();
            int n = in.nextInt();
            sb.setLength(0);
            for(int j=0; j<n; ++j) {
                // 2^0 + 2^1 + ... 2^j = 2^(j+1) - 1
                sb.append((int) (a + b*(Math.pow(2, j+1) - 1))).append(" ");
            }
            System.out.println(sb.toString());
        }
        in.close();
    }
}
    • Liswin + 1 comment

      What does variable 't' hold in this program?

      • sleepzilla23 + 1 comment

        The number of queries, which is the integer on the first line of the input.

        • ayushbarnawal48 + 1 comment

          then what's about n? I'm confuse in between these two. Can you please explain.

          • _Syarif_ + 0 comments

            2 3 3 4 5 6 5 7 n = 8

    • mysidia + 3 comments

      I didn't need to call the Math.pow() function.

      I used

      for(x = 0; x < n; x++) {
    result = a;
    for(h = 0; h <= x; h++)
        result += (1<< h) * b; 
    if ( x > 0)  System.out.printf(" ");
    System.out.printf("%d", result);
} System.out.printf("\n");
      • sruthi_15821 + 1 comment

        what does this line(result += (1<< h) * b) do? what is the role of << operator?

        • mysidia + 2 comments

          a += b; is the same as a = a + b;

          (1<<h) Starts with 2 to the zeroth power, a binary 1, Shifts the number to the left by h binary bits, e.g 00000001 in binary left shift 1 becomes 00000010, left shift 2 becomes 00000100.

          Left-shifting a binary number by 1 bit position multiplies that number by 2. Left-shifting by 2 multiplies by 2^2. Left-shifting by 3 multiplies by 2^3, etc.

          • sruthi_15821 + 0 comments

            thankyou..

          • niktor + 0 comments

            nice idea with the binary shift!

      • nagireddy030493 + 0 comments

        for(int i=0;i 

            sum= sum+b;
     System.out.print(sum+" ");
        b=2*b;
    }

     System.out.println("");
}
in.close();
      • sisolta75 + 0 comments

        Should be h<=x+1

    • gourabinda + 0 comments

      whats that String builder means?