I upvoted the blog and participated. I guess the scientific studies and their evidences for longevity and happiness are wrong :(

I have the same problem, I will tell you what I have been doing to solve this. Generally while implementing, you may find that you had the idea and logic how to solve but the code gets stuck. You can start solving implementation problems that are available in the problem set section, moreover what I try to do is I implement the same problem in 2-3 ways that all yield the answer. This way you will get more grasp of writing the code instead of just thinking of logic. Any more suggestions are highly appreciated.

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Hello team and MikeMirzayanov! This is the first time that I have got a message that my submission is being charged for plagiarism. My submission id is 114028312, I didn't know that we're not supposed to use ideone but I am pretty sure that I haven't cheated or tried to provide solutions to anyone. I request you to provide further steps, i.e. what do I need to do further. Thanks.

I have the same doubt... I got this for 1517B. I guess you need to prove it somewhere but I don't know where to. Expecting for a reply on this.

In problem C, I didn't use the graph approach and instead used for loop traversals to go through the array a like this:

for(int i=0;i<n;i++){

if(a[i]>b[i]){

            count=-1;

            flag=1;

        }
    }
    if(flag!=1){
    for(int i=0;i<n;i++){
        if(a[i]!=b[i]){
            char h=a[i];
            for(int j=i+1;j<n;j++){
                if(a[j]==h && a[j]!=b[j]){
                    a[j]=b[i];
                }
            }
            a[i]=b[i];
            count++;
        }
    }
    }

Can anybody please tell me what's wrong in this?