Count and say problem | Love Babbar DSA Sheet | Leetcode | Amazon | Google🔥

#competitiveprogramming #dsasheet #interviewpreparation

In this video I have solved the problem of the sheet i.e. Count and say problem.
Complete Explaination with code.

Hope you like it. Comment if you have any doubt

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[shubhamdixit]

When I read the question specifics on leetcode, I just said, what Rubbish this question. But I then realised after seeing this video that the question is still more rubbish and I just misunderstood it the last time. Anyways nice explanation to the problem itself man

[black_jack_meghav]

the best solutions videos on yt. no nonsense, to the point short sweet. thanks men, you guys deserve more subs!!

[debangshudey]

public String countAndSay(int n) {
String s="1";
for(int i=2;i<=n;i++){
s=countAndAdd(s);
}
return s;

}
public String countAndAdd(String s)
{
StringBuilder str=new StringBuilder();
char c=s.charAt(0);
int count=1;

for(int i=1;i<s.length();i++)
{
if(s.charAt(i)==c) count++;

else{
str.append(count);
str.append(c);
c=s.charAt(i);
count=1;
}
}
str.append(count);
str.append(c);

return str.toString();
}

[karankakkar]

Python solution :
def count_and_say(n):
if n == 1:
return "1"
s = count_and_say(n - 1)
res = ""
counter = 0

for i in range(0, len(s)):
counter += 1
if i == len(s) - 1 or s[i] != s[i + 1]:
res = res + str(counter) + s[i]
counter = 0

return res

[shobitsharma]

My code using
string solve(int n){
if(n==1)return "1";
string p=solve(n-1);
string ans="";
int count=1;
for(int i=1;i<p.size();i++){
if(p[i]==p[i-1])count++;
else{
ans+=to_string(count);
ans+=p[i-1];
count=1;
}
}
ans+=to_string(count);
ans+=p[p.size()-1];
return ans;
}
string countAndSay(int n) {
return solve(n);
}

[dataman]

any option to reduce the time complexity? This solution somehow looks naive.

[kms]

Hi, I have one small doubt that why we add '&' or '$' at the end of the string, could you please explain this again?

[prathamgwari]

Nice Explanation! 1:04 pe hi samajh aa gya ki code kaise likhna hai :) .

Here is the code:

string GetNextNum(string num)
{
int ctr = 1;
int lastNum = num[0];
string nextNum;
int i;
for(i=1; i<num.size(); i++)
{
if(num[i] == lastNum)
{
ctr++;
}
else
{
nextNum += to_string(ctr) + num[i-1];
ctr=1;
lastNum = num[i];
}
}
nextNum += to_string(ctr) + num[i-1];
return nextNum;
}

string Solution::countAndSay(int A)
{
string nextNum = "1";
for(int i=0; i<A-1; i++)
{
string num = nextNum;
nextNum = GetNextNum(num);
}
return nextNum;
}

[SHAUMAYAOJHABCE]

keep doing it man, love your videos, will be great help for others also

[lokeshnegi]

i think u should explain in brief why u are using delimiter.
that would be really helpful

[Rahul_Mongia]

//JAVA SOLUTION
class Solution {
public String countAndSay(int n) {
if(n<=0)
{
return null;
}

String result="1";
int i=1;

while(i<n)
{
StringBuilder sb=new StringBuilder();

int count=1;

for(int j=1;j<result.length();j++)
{

{
count++;
}
else
{
sb.append(count);



count=1;
}

}
sb.append(count);


result=sb.toString();
i++;
}
return result;
}
}

[satyapraneethkatta]

thanks a lot, Bhai !! The best explanation for this problem on youtube

[shubham]

Bro just a suggestion, plz explain the thorough intution, in the video there was just, about how to do the question, like this is the aldo and this is the code, there is no explanation to anything...

[kirtanprajapati]

bro great explanation dry run bhi ho gya but yar ese think kese krna he matlab itna jyada sayad khudse kabhi soch hi nhi pata esa matlab esa sochna kese he bta skte he app ? plz

[kailashjangir]

for your code it's showing wrong answer, why??

[prashantsoni]

easiest solution..we don't need & or any $ symbol


..

class Solution {
public:
string countAndSay(int n)
{
if(n==1)
{
return "1";
}
if(n==2)
{
return "11";
}
string s="11";
int i;
for(int j=3;j<=n;j++)
{
string t="";
int count=1;
for( i=0;i<s.length()-1;i++)
{
if(s[i]!=s[i+1])
{
t=t+to_string(count);
t=t+s[i];
count=1;
}
else
{
count++;
}
}
t=t+to_string(count);
t=t+s[i];
s=t;
}
return s;
}

};

[ajvlogs]

i think its not the optimized approach as we are using nested loops

[gorakhkumargupta]

bro why u have inserted delemter like $ in the string

[karthikprabhu_career]

In the 7th line, why does the loop start from 3 ?? What is the purpose of this loop?

[pankajpatil]

Thank you so much love babbar cracker sheet shuru karne ke liye🙏🙏👍