In this blog, I will explain how to ace the Google interview for a Software Engineering (SWE) intern position, including how to prepare and approach problem-solving effectively

I am an upcoming SWE intern in Google so I am credible enough to answer this question based on my experience and understanding of the interview process.

Interview Tips

• Make it a habit to write your code on Notepad or Google Docs, This is important because the autocomplete features and other helpful coding tools that you may rely on during your regular coding sessions will not be available in the interview setting

• Ensure your variable names are as descriptive and meaningful as possible to improve code readability and help the interviewer follow your logic.

    Don't use 
    int n=arr.size() use instead int arraySize=arr.size();
    for(int i=0;i<n;i++) use instead for(arrayIndex=0;arrayIndex<arraySize;arrayIndex++)

• Speak about what you are doing while writing code, so that the interviewer does not lose interest and does not feel bored. Also, do not hesitate to take hints if you are stuck somewhere.

• Make sure to carefully read the problem statement to avoid wasting time-solving the wrong question or misunderstanding key requirements.

• If you don't understand any part of the problem statement, ask the interviewer for clarification. This won't leave a negative impression

• Declare functions that perform specific tasks, increasing code readability and making your solution easier to follow and maintain and make the function name which is related to what it does.

    Don't use 
    int f(int a,int b) use instead int sumOfNumber(int number1,int number2)

• Make sure you have a better understanding of the time complexity of each data structure, such as map, unordered map, set, unordered set, and disjoint set union, etc as this will help you analyze their time complexities effectively.

• practice important topics related to graphs, as they are highly valued in interviews. Google particularly favors graph-related problems, so it is essential to prepare these topics thoroughly to ensure a strong understanding and proficiency.

    topics:
    depth-first search,breadth-first search, shortest path algorithm, toposort, disjoint-set-union etc.

I have documented the strategy I used during my Google interview, highlighting the key approaches and techniques that helped me succeed.

If you have any questions regarding the strategies I've shared, I warmly welcome you to ask them in the comments or in instagram. I'm here to help and provide any clarification you may need! instagram

I truly hope you find this information enjoyable and helpful in your preparation journey.

The below article is an attempt to create a good starting point for people who practice some good DSU problems

you read the Nice blog by kartik8800 DSU Blog here you tell basics to advanced about DSU

below code is written by striver you can take reference from his YT channel TAKE U FORWARD

striver_79

disjointset(int n){
   rank.resize(n+1,0);
   parent.resize(n+1);
   size.resize(n+1);

   for(int i=0;i<n;i++){
      parent[i] = i;
      size[i] = 1;
   }
}

int findUPar(int node){
   if(node == parent[node]){
      return node;
   }
   return parent[node] = findUPar(parent[node]);
}

void unionBySize(int u,int v){
   int ulp_u = findUPar(u);
   int ulp_v = findUPar(v);
   if(ulp_u == ulp_v) return;
   if(size[ulp_u] < size[ulp_v]){
      parent[ulp_u] = ulp_v;
      size[ulp_v]+=size[ulp_u];
   }
   else{
      parent[ulp_v] = ulp_u;
      size[ulp_u]+=size[ulp_v];
   }
}

#### PROBLEM 1

1 -> This Problem Based how we can use DSU beautifully by sorting the edges of the graph

1213G - Path Queries

ll upar(ll x){
    if(parent[x]==x)return x;
    return parent[x]=upar(parent[x]);
}

void merge(ll a,ll b){
    a=upar(a),b=upar(b);
    if(a==b)return;
    ll psize=size[a];
    size[a]+=size[b];
    parent[b]=a;
    ans+=(ncr(size[a])-ncr(size[b])-ncr(psize));
} 

Check my submission

#### PROBLEM 2

2 -> This Problem is easy side of DSU to make the network connected

25D - Roads not only in Berland

ll upar(ll x){
    if(parent[x]==x)return x;
    return parent[x]=upar(parent[x]);
}

void merge(ll a,ll b){
    a=upar(a);
    b=upar(b);
    parent[b]=a;
    size[a]+=size[b];
}

Check my submission

#### PROBLEM 3

3 -> you have to make forest by adding edges by making two DSU

1559D1 - Mocha and Diana (Easy Version)

ll upar(ll x){
    if(parent[x]==x)return x;
    return parent[x]=upar(parent[x]);
}

void merge(ll a,ll b){
    a=upar(a);
    b=upar(b);
    parent[b]=a;
    size[a]+=size[b];
}

Check my submission

#### PROBLEM 4

4 -> This Problem Based how we can minimise the or of the no by making highest bit to Zero

1624G - MinOr Tree

ll upar(ll x){
    if(par[x]==x)return x;
    return par[x]=upar(par[x]);
}

void merge(ll a,ll b){
    a=upar(a);b=upar(b);
    if(a==b){
       return;
    }
    par[b]=a;
    size[a]+=size[b];
}

ll sz(ll x){
    return size[upar(x)];
}

Check my submission

#### PROBLEM 5

5 -> This Problem Based how we can use DSU to connect the edges from edge weight form low to high

1468J - Road Reform

ll upar(ll x){
    if(par[x]==x)return x;
    return par[x]=upar(par[x]);
}

bool merge(ll a,ll b){
    a=upar(a);b=upar(b);
    if(a==b){
       return 0;
    }
    par[b]=a;
    size[a]+=size[b];
    return 1;
}

ll sz(ll x){
    return size[upar(x)];
}

Check my submission

this is good level 5 problem enough to Grasp the concepts if you want to try more prblem try this Codeforces DSU Problems

ALL THE BEST FOR YOUR CODING JOURNEY :)