Hello Everyone, Can anyone clarify when we are using binary search. Sometimes in the while loop We write while(l<r) and sometimes we write while (l<=r) depending from question to question ofc.

But I always get pretty confused between the two and ended up either wasting too much time or making many wrong submissions. is there a clear cut distinction like when we should use the first one and when we should use the second one?

Questions like these confuses me a lot https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/

Thanks!

There is exactly one character ( and exactly one character ) .

This should be There is exactly one character '(' and exactly one character ')'.

I wasted an hour on this :/.

Anyone know how to come up with these kind of solutions?, because intuitively its not easy and took me a while Thanks!

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

int32_t main(){

int t;
cin>>t;

while(t--){
    

    int n,q;
    cin>>n>>q;
    int a[n];
    for(int i =0; i<n; i++){
           cin>>a[i];
        }

int ans =a[0];


for(int i=1; i<n; i++){
   int x = a[i]-a[i-1];
   
   if(x>0){


    ans+=x;   

  }

    
  else continue;


}
cout<<ans<<endl;
}




}

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Hey, So have just started youtube channel, where I will be solving all the contests problems( primarily div2 and div3 ). Will Basically be speaking Hinglish. Here is the link. https://www.youtube.com/channel/UC4o7r8KS9BCt-pt0rR5Yfgg?view_as=subscriber

Thanks!