LUCKFOUR - editorial

general
,
23

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

class Codechef
{
	public static void main (String[] args) throws java.lang.Exception
	{
        Scanner sc = new Scanner(System.in);
        int t = sc.hasNextInt()?sc.nextInt():0;
        for(int i=0;i<t;i++){
            String s = sc.hasNext()?sc.next():"";
            int count= 0;
            for(int j = 0;j<s.length();j++){
                count= s.charAt(j)=='4'?count+1:count;
            }
            System.out.println(count);
    	}
	}
}
24

my code worked in python 2.7.13
check out this code for your reference:

x=int(input())
for i in range(x):
n=int(input())
count=0
while(n>0):
res=n%10
if(res==4):
count=count+1
n=n/10
print(count)

25

I don’t understand what I’ve to do under Subtasks 1 and 2. Can someone help me out? I have identified the frequency of 4s present in my numeral and that part works perfectly

26

link to solution
- YouTube

27

its not working

28

bro i dont understand ur logic explain plz

29

I used string instead of integer in each test case

#include <bits/stdc++.h>
using namespace std;

int main()
{
int t;
cin>>t;
cin.ignore();
while(t–){
string s;
cin>>s;
int count=0;
for (int i = 0; i < s.size(); ++i)
{
if ((s[i]-‘0’)==4)
{
count=count+1;
}
}

	cout<<count<<endl;

}

}

30

Okay so what I did is I took the input of each test case as string and ran a for loop from 0 to length of the string -1 and compared each of the index of string string with 4 whenever I found 4 I increased the count and finally printed the count

31

I don’t know what to do, please help me:

process.stdin.resume();
process.stdin.setEncoding(‘utf8’);

// your code goes here

process.stdin.on(‘data’, data => {
let userInput = data.toString();
let long = userInput.replace(/\s/g,".");
let arr = long.split(’.’);

const t = arr[0];
let a = 0;
let par1 = 1;
let count = 0;

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

    a = arr[par1].split('');
    
    for(let i = 0; i < a.length; i++){
        
        if (a[i] === '4'){
            count += 1;
        }
    }
    
    console.log(count);
    par1 += 1;
    count = 0;
}
process.exit();

});

32

While submitting the solution to the problem, I am getting an error with message “Solution to this problem cannot be submitted now”. .

33

Can you please share a screenshot or video of the full page?

34

constrains
1≤ T≤ 105

  • (Subtask 1): 0 ≤ Numbers from the list ≤ 9 - 33 points.
  • (Subtask 2): 0 ≤ Numbers from the list ≤ 109- 67 points.

i don’t understand what subtask 1 and 2 mean here?

I was using C++ and in the reference code they used long long for all variables instead of int. why is it so?
without using long long , my code got submitted.