M. Subsequence String (##)

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

int main()
{
   string s;
   cin>>s;
   string h="hello";

   int i=0;
   int j=0;

   while(true){
    if(i==s.size() || j==h.size()) break;
    if(s[i]==h[j]) j++;   //increase j if there is a match, we are just iteratign voer s and check if hello can be subsequence a possibiltiy
    i++;
   }
   if(j==5) cout<<"YES";    //if jturns out to be 5 then we travelled through hello fully as well
   else cout<<"NO";
   
    return 0;
}


LOGIC: Take a string and assign it a value "hello".Take two int variables i and j. Set both to zero. 
They will represent the index of current character on the input string and index of the current char on the string hello
Iterate on the input string and every time u encounter a char equal to char to which the j variable points, increment j. 
It means that we have got the char at index j and now we will search for the next character.
At last after the loop ends check if the j variable has a val equal to 5 or not.  
If it is 5 then it means all the characters of hello were encountered in order. So print yes


Link - https://codeforces.com/group/MWSDmqGsZm/contest/219856/problem/M