Leetcode Weekly contest 346 - Medium - Find the Punishment Number of an Integer

In this video we discuss the third problem of Leetcode Weekly contest 346

[RishabhJain-elhh]

Yeah, Thanks bhaiya, good solution actually tried using maths but at last did it using recursion

[genghisda]

how did you import the webpage into notes app of ipad ?

[mehtaneelkumarhirenkumar]

hii bhaiya, how did you solve question very easily?how did you prepare?

[RishabhJain-elhh]

Here is my approach:-

class Solution {

boolean isPossible(int id, int sum, String s){

if(id==s.length() && sum==0)return true;

for(int i=id;i<s.length();i++){

String str=s.substring(id, i+1);
int val=Integer.parseInt(str);

if(val<=sum){

boolean f=isPossible(i+1, sum-val, s);
if(f==true)return true;
}
}
//kahin se bhi true nhi aaya
return false;



}
public int punishmentNumber(int n) {

int sum=0;
for(int i=1;i<=n;i++){
int sq=i*i;
String s=""+sq;
int maxSum=i;

boolean f=isPossible(0, maxSum, s);
// System.out.println(s +" "+sq+" "+maxSum);
// System.out.println(f+" for "+" "+i);
if(f==true)sum+=sq;
}

return sum;

}
}