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[Challenge] Palindromic Sum
The palindromic number 595 is interesting because it can be written as the sum of consecutive squares: 6^2+7^2 +8^2 +9^2 +10^2+ 11^2+12^2. There are exactly eleven palindromes below one-thousand that can written as consecutive square sums, and the sum of these palindromes is 4164. Note that 1 = 0^2 + 1^2 has not been included as this problem is concerned with the squares of positive integers. Find sum of all numbers less than 10^8 that are both palindromic & can be written as t
3 Respostas
+ 10
you can better use playground to post codes 😃
+ 2
proposed 10 days ago...at least try finding new ones !
- 2
/*
Description: The code finds sum of all  numbers less than 10^8 that are both palindromic & can be written as the sum of consecutive squares 
*/
import java.util.ArrayList;
import java.util.Collections;
public class PalindromicSum{
public static void main(String...arg){
   int n=100_000_000;
   System.out.println("Test case for n < 1000 :");
   FindSum((int)Math.sqrt(1000),1000);
   System.out.println("\n\nOutput for n < 10^8 :");
   FindSum((int)Math.sqrt(n),n);
}
static void FindSum(int sqrtN,int N){
    long sum=0; 
    ArrayList<Integer>list=new ArrayList<>(); 
    for(int i=1;i<=sqrtN;i++){ 
        int n=i*i; 
        for(int j=i+1;j<=sqrtN;j++){ 
            n+=j*j; 
            if(n>N) break; 
            if(IsPalindrome(n)&&!list. contains(n)){ 
                sum+=n;
                list.add(n);
            }
        } 
    }
    Collections.sort(list);
    System.out.print("Total sum = "+sum+"\nList of numbers:\n"+list);
}
static boolean IsPalindrome(int n){ 
    int r=0,i=n; 
    while(i>0){ 
        r=10*r+i%10; 
        i/=10; 
    } 
    return n==r; 
}
}



