TWTCLOSE - Editorial

ashryaagr · July 19, 2018, 6:20pm

I am unable to understand what is wrong with this solution : CodeChef: Practical coding for everyone
When i run this program it shows : Exception in thread “main” java.lang.StringIndexOutOfBoundsException: String index out of range: 7
at java.base/java.lang.StringLatin1.charAt(StringLatin1.java:44)
at java.base/java.lang.String.charAt(String.java:692)
at numberOfOpenTweets.main(numberOfOpenTweets.java:16)
So if you can spot the error please tell

orderof1 · June 18, 2012, 1:58am

Memset would also take O(N) time to go through each element. But yes, the actual time might be lesser.
For every CLOSEALL, we do not do anything if number of tweets is 0. That could help but doesn’t lower worst case time.

vikram535 · June 18, 2012, 1:04pm

I used memset for filling 0s. My solution was showing wrong answer though I have implemented it same as mentioned in the tutorial.
http://www.codechef.com/viewsolution/1132512
Can’t find what is the difference

flying_ant · June 18, 2012, 1:16pm

@vikram535 : Please check the ‘memset’ function in the library. The last parameter should be the number of bytes, and not number of elements in the array. If your array is int A[1001]; , you should use it as, memset(A,0,sizeof(A));

betlista · June 18, 2012, 2:12pm

You meant for example O(1/2 * N)? In fact that doesn’t matter, it’s asymptotically O(N).

vikram535 · June 18, 2012, 4:21pm

Thank you so much for pointing out my mistake. I was not able to find it. Thanks again

betlista · October 5, 2012, 7:31pm

here is counter example - A6o21 - Online Java Compiler & Debugging Tool - Ideone.com

herman · October 5, 2012, 7:49pm

hey thnx…my mistake i didn’t observe dat…thnx a lot…

betlista · March 20, 2014, 2:58pm

Your class cannot be public, that’s the first problem at CodeChef. In addition

int c = Integer.parseInt(t1.substring(n - 1, n));
c = c - 1;

smells - J3TYWf - Online IDE & Debugging Tool - Ideone.com

rishabhprsd7 · December 2, 2014, 1:19pm

@ajinkya1p3

You forgot to print number of open tweets after input “CLOSEALL”

I have added print statement and here’s the accepted version of your code

http://www.codechef.com/viewsolution/5479172

ajinkya1p3 · December 2, 2014, 1:55pm

Thanks a lot!!

rishabhprsd7 · December 2, 2014, 2:14pm

most welcome

ak1010 · June 8, 2019, 9:09am

I did it in a similar way and the answer is submitted

#include
#include
#include
#include
using namespace std;
int main ()
{ ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n,k;
cin>>n>>k;
std::string str;
std::bitset<1000> boo;
while(k–){
cin>>str;
if(str ==“CLOSEALL”){
boo.reset();
cout<<0<<"\n";

}
else{
    int c;
    cin>>c;
    boo = boo.flip(1000-c);
    cout<<boo.count();
    cout<<endl;
}

}

return 0;
}

bing_ambar · July 3, 2019, 5:28pm

Can anyone help me out here? I’m getting wrong answer status. What’s wrong in my code?
https://www.codechef.com/viewsolution/25035176

shim98 · July 4, 2019, 5:05am

you didn’t consider elements bigger than 9
your code will fail on those test cases

bing_ambar · July 5, 2019, 9:38am

Thank you for pointing it out. It was kind of a silly mistake. Here’s the correct one.
https://www.codechef.com/viewsolution/25048355

shubhulol · August 30, 2019, 9:38am

This code is giving NZEC error Please help me

class TWTCLOSE {

    int result = 0;
static int Program(String str, int val, int[] arr) {
	if (arr[val] == 0) {
		arr[val] = 1;
		result++;
	} else {
		arr[val] = 0;
		result--;
	}
	return result;
}

public static void main(String[] args) throws IOException {
	java.io.BufferedReader r = new java.io.BufferedReader(new java.io.InputStreamReader(System.in));
	int n = 0;
	int k = 0;
	n = r.read();
	r.readLine();
	k = r.read();
	r.readLine();
	int[] arr = new int[Character.getNumericValue(n)];
	k = Character.getNumericValue(k);
	if (n >= 1 && k <= 1000) {
		while (k > 0) {
			String str = r.readLine();
			int length = str.length();
			str.trim();
			if (str.equalsIgnoreCase("closeAll")) {
				System.out.println("0");
				Arrays.fill(arr, 0);
				result = 0;
			} else {
				int val = Integer.parseInt((str.substring(length - 1, length)));
				System.out.println(Program(str, val-1, arr));
			}
			k--;
		}
	}
}

}

manjot1151 · January 1, 2020, 2:40pm

This is how I did it in Java.

class Codechef {

  public static void main (String[]args) throws java.lang.Exception
  {
    // your code goes here
    Scanner in = new Scanner(System.in);
    int n=in.nextInt();
    int k = in.nextInt();
    in.nextLine();
    int ans=0;
    int[] a = new int[n];
    for (int i=0;i<k;i++)
    {
        
        String s=in.nextLine();
        if (s.charAt(2)=='O')
        {
            ans=0;
            a = new int[n];
        }
        else
        {
            int l=s.length();
            String numstr=s.substring(6);
            int num=Integer.parseInt(numstr);
            
            
            if (a[num-1]==0)
            {
                a[num-1]=1;
                ans++;
                
            }
            else 
            {
                a[num-1]=0;
                ans--;
            }
        }
        System.out.println(ans);
    }
  }
}

harshraj22 · February 12, 2020, 6:20pm

I am getting TLE using React Js. I am new to this language. Can anyone help ?
My code

dk3xploiter · July 22, 2020, 9:20am

x,t = map(int,input().split())
st=""
while(t):
s = input()
if(“ALL” in s):
st=""
else:
for i in range(1,x+1):
if(str(i) in s):
if(str(i) in st):
st = st.replace(str(i),"",1)
else:
st+=str(i)
# print(st)
print(len(st))
t-=1

what is wrong in this pls help me