LeetCode, GeeksForGeeks Problem of the day solution

class Solution{ public: int DivisibleByEight(string s){ int n = s.size(); if(n<=3){ int a = stoi(s); if(a%8==0)return 1; else return -1; } string lastThreeDigit = s.substr(n-3,3); int a = stoi(lastThreeDigit); return a%8==0?1:-1; } };

class Solution { public: pair solve(TreeNode* root){ if(root==NULL)return {0,0}; pair left=solve(root->left); pair right=solve(root->right); int a=left.first; int b=right.first; int c=left.second+right.second; pair ans; ans.first=max(a,max(b,c)); ans.second=max(left.second,right.second)+1; return ans; } int diameterOfBinaryTree(TreeNode* root) { return solve(root).first; } };

int* game_with_number(int arr[], int n) { for(int i=0;i

class Solution { public: bool isSameTree(TreeNode* p, TreeNode* q) { if(p==NULL || q==NULL){ return p==q; } return (p->val == q->val) && isSameTree(p->left, q->left) && isSameTree(p->right, q->right); } };

class Solution{ void solve(int ind, string &s, string &ds, vector &ans){ if(ind >= s.size()){ if(ds.size() > 0) ans.push_back(ds); return; } ds.push_back(s[ind]); solve(ind + 1, s, ds, ans); ds.pop_back(); solve(ind + 1, s, ds, ans); } public: vector AllPossibleStrings(string s){ // Code here vector ans; string ds; solve(0, s, ds, ans); sort(ans.begin(), ans.end()); return ans; } };

#define ll long long const ll MAX = 1e5 + 5; bool prime[MAX]; ll spf[MAX]; void sieve(){ fill(prime, prime+MAX, true); for(int i=1;i<MAX;i++){ spf[i] = i; } prime[0] = prime[1] = false; for(ll i=2;i*i<MAX;i++){ if(prime[i]){ for(ll j=i*i;j<MAX;j=j+i){ if(prime[j]){ spf[j]=i; } prime[j] = false; } } } } vector<ll> getFactorization(ll x){ vector<ll> ret; unordered_map<ll, ll> mp; while(x != 1){ mp[spf[x]]++; x = x/spf[x]; } for(auto it:mp){ ret.push_back(it.first); // ret.push_back(it.second); } return ret; } class Solution { public: void dfs(int node, vector<ll> adj[], ll& cnt, vector<int>& vis){ vis[node] = 1; cnt++; for(auto it:adj[node]){ if(vis[it]==0){ dfs(it, adj, cnt, vis); } } } bool canTraverseAllPairs(vector<int>& nums) { sieve(); int n = nums.size(); unordered_map<ll, vector<ll>> mp; for(ll i=0;i<n;i++){ mp[i] = getFactorization(nums[i]); } unordered_map<ll, vector<ll>> rmp; for(auto it:mp){ ll ind = it.first; for(auto prime:it.second){ rmp[prime].push_back(ind); } } vector<ll> adj[n]; for(auto it:rmp){ vector<ll> ind=it.second; if(ind.size()<2){ continue; } for(ll i=1;i<ind.size();i++){ int u = ind[i-1]; int v = ind[i]; adj[u].push_back(v); adj[v].push_back(u); } } ll cnt=0; vector<int> vis(n, 0); dfs(0, adj, cnt, vis); return cnt==n; } };

class Solution { public: // Complete this function long long int count(long long int n) { // Your code here vectordp(n+1,0); dp[0] = 1; for(int i=3;i<=n;i++){ dp[i] +=dp[i-3]; } for(int i=5;i<=n;i++){ dp[i] +=dp[i-5]; } for(int i=10;i<=n;i++){ dp[i] +=dp[i-10]; } return dp[n]; } };

class Solution { public: vector findAllPeople(int n, vector>& meetings, int firstPerson) { vector ans; ans.push_back(0); vector secretTime(n,INT_MAX); secretTime[0]=0; secretTime[firstPerson]=0; unordered_map>> adj; for(int i=0;i q; q.push(0); q.push(firstPerson); while(!q.empty()){ int person1=q.front(); q.pop(); for(auto i : adj[person1]){ int person2=i.first; int meetingTime=i.second; if(meetingTime>=secretTime[person1]&&meetingTime < secretTime[person2]){ secretTime[person2]=meetingTime; q.push(person2); } } } for(int i=1;i

class Solution { public: int maxSum(int n) { if((n/2+n/3+n/4)<=n) return n; return maxSum(n/2)+maxSum(n/3)+maxSum(n/4); } };

class Solution { public: int findCheapestPrice(int n, vector>& flights, int src, int dst, int k) { vector> adjList[n]; for(vector edge: flights) { adjList[edge[0]].push_back({edge[1], edge[2]}); } vector distance(n, 1e7); queue> Queue; Queue.push({src, 0}); distance[src] = 0; while(k >= 0 && !Queue.empty()) { int sz = Queue.size(); for(int i = 0; i < sz; i++) { pair curr = Queue.front(); Queue.pop(); for(pair edge: adjList[curr.first]) { int next = edge.first; int weight = edge.second; int cost = curr.second + weight; if(cost <= distance[next]) { distance[next] = cost; Queue.push({next, cost}); } } } k--; } return distance[dst] == 1e7? -1: distance[dst]; } };