created project euler

Author: kothariji

Data Structures and Algorithms/Graph/(HACKEREARTH) Feasible relations.cpp

@@ -0,0 +1,70 @@
+#include <bits/stdc++.h>
+#define lli int
+#define endl "\n"
+#define MAX 1000005
+using namespace std;
+
+vector <lli> visited(MAX, -1);
+int counter;
+
+void DFS(lli i, vector < vector<lli> > v1)
+{
+	visited[i] = counter;
+	for(int j = 0; j<v1[i].size(); j++)
+		if(visited[v1[i][j]] == -1)
+			DFS(v1[i][j], v1);
+}
+
+int main()
+{
+	lli t;
+	cin>>t;
+	ios_base::sync_with_stdio(false);
+	cin.tie(NULL);
+	while(t--)
+	{
+		lli n, k, num1, num2;
+		cin>>n>>k;
+		vector < vector<lli> > v1(n+1);
+		vector <pair <lli, lli> > notequal;
+		string s;
+		for(lli i = 0; i<k; i++)
+		{	
+			cin>>num1>>s>>num2;
+			if(s[0] == '=')
+			{
+				v1[num1].push_back(num2);
+				v1[num2].push_back(num1);
+			}
+			else {
+				notequal.push_back({num1, num2});
+			}
+		}
+
+		for(lli i =0 ;i <=n; i++)
+			visited[i] = -1;
+		counter = 0;
+		for(lli i =1; i<=n; i++)
+		{
+			if(v1[i].size() > 0)
+			{
+				if(visited[i] == -1)
+				{
+					counter++;
+					DFS(i, v1);
+				}
+			}
+		}
+		bool ans = true;
+		for(auto c: notequal)
+			if((visited[c.first] == visited[c.second]) && (visited[c.first] != -1))
+			{
+				ans = false;
+				break;
+			}
+		if(ans)
+			cout<<"YES"<<endl;
+		else
+			cout<<"NO"<<endl;
+	}
+}

Data Structures and Algorithms/Graph/(SPOJ) Prime Path.cpp

@@ -0,0 +1,97 @@
+#include <bits/stdc++.h>
+#define lli long long int
+#define endl "\n"
+#define MAX  100005
+using namespace std;
+
+vector <bool> visited(MAX, false);
+vector <lli> dist(MAX, -1);
+vector < vector <lli> > v1(MAX);
+vector <lli> primes;
+
+bool isprime(lli n)
+{
+	for(lli i =2; i*i <=n; i++)
+		if(n%i == 0)
+			return false;
+	return true;
+}
+
+bool valid(lli a, lli b)
+{
+	lli dif = 0;
+	string s1 = to_string(a);
+	string s2 = to_string(b);
+	if(s1.length() != s2.length())
+		return false;
+	for(lli i =0; i<4; i++)
+		if(s1[i] != s2[i])
+			dif++;
+
+	if(dif == 1)
+		return true;
+	return false;
+}
+
+void buildprimes()
+{
+	for(lli i = 1000; i<10000; i++)
+		if(isprime(i))
+			primes.push_back(i);
+}
+
+void buildgraph()
+{
+	for(lli i = 0; i<primes.size()-1; i++)
+		for(lli j = i+1; j<primes.size(); j++)
+		{
+			if(valid(primes[i], primes[j])){
+				v1[primes[j]].push_back(primes[i]);
+				v1[primes[i]].push_back(primes[j]);
+			}
+		}
+}
+
+int main()
+{	
+	lli t;
+	cin>>t;
+	
+	buildprimes();
+	buildgraph();
+	while(t--)
+	{
+		lli n1, n2;
+		cin>>n1>>n2;
+		for(lli i = 1000; i<10000; i++)
+		{
+			visited[i] = false;
+			dist[i] = -1;
+		}
+		visited[n1] = true;
+		dist[n1] = 0;
+
+		queue <lli >q1;
+		q1.push(n1);
+
+		while(!q1.empty())
+		{
+			lli temp = q1.front();
+			q1.pop();
+			for(lli j = 0; j<v1[temp].size(); j++)
+			{
+				if(visited[v1[temp][j]] == false)
+				{
+					visited[v1[temp][j]] = true;
+					q1.push(v1[temp][j]);
+					dist[v1[temp][j]] = dist[temp] + 1;	
+				}
+			}
+		}
+
+		if(dist[n2] != -1)
+			cout<<dist[n2]<<endl;
+		else
+			cout<<"Impossible"<<endl;
+	} 
+}

Project Euler (HackerRank)/001. Multiples of 3 and 5.cpp

@@ -0,0 +1,27 @@
+#include <bits/stdc++.h>
+#define lli long long int 
+using namespace std;
+
+
+int main() {
+    
+    int t;
+    cin>>t;
+    while(t--)
+    {
+        lli n, sum = 0,num=0,i=0; 
+        cin>>n;
+        n--;
+        lli n3 = n/3; 
+        lli n5 = n/5;
+        lli n15 = n/15;
+        lli sum3 = ((n3)*(n3+1))/2;
+        lli sum5 = ((n5)*(n5+1))/2;
+        lli sum15 = ((n15)*(n15+1))/2;
+        lli ans3 = 3*sum3;
+        lli ans5 = 5*sum5;
+        lli ans15 = 15*sum15;
+        cout<<ans3+ans5-ans15<<endl;  
+    } 
+    return 0;
+}

Project Euler (HackerRank)/002. Even Fibonacci numbers.cpp

@@ -0,0 +1,26 @@
+#include <bits/stdc++.h>
+#define lli long long int
+using namespace std;
+
+
+int main() {
+    int t;
+    cin>>t;
+    while(t--)
+    {
+        lli n,sum=2,prev = 0,num=2,newnum;
+        cin>>n;
+        while(1)
+        {
+            newnum = (num*4) + prev;
+            prev = num;
+            num = newnum;
+            if(num <= n)
+                sum += num;
+            else
+                break;    
+        }
+    cout<<sum<<endl;
+    }
+    return 0;
+}

Project Euler (HackerRank)/003. Largest prime factor.cpp

@@ -0,0 +1,34 @@
+#include <bits/stdc++.h>
+#define lli long long int
+#define endl "\n"
+using namespace std;
+
+lli pf(lli n)
+{
+    priority_queue <lli> pq;
+    for(lli i=2; i*i<=n;i++)
+    {
+        if(n%i==0)
+        {
+            pq.push(i);
+            while(n%i ==0)
+                n /= i;
+        }
+    }
+    if(n > 1)
+        return n;
+        else
+        return pq.top();
+}
+
+int main() {
+    int t;
+    cin>>t;
+    while(t--)
+    {
+        lli n;
+        cin>>n;
+        cout<<pf(n)<<endl;
+    }
+    return 0;
+}

Project Euler (HackerRank)/004. Largest palindrome product.cpp

@@ -0,0 +1,58 @@
+#include <bits/stdc++.h>
+#define lli long long int
+using namespace std;
+
+bool ispalin(string s, int i ,int  j)
+{
+    if(i >= j)
+        return true;
+    if(s[i] != s[j])
+        return false;
+    
+    return ispalin(s, i+1 , j-1); 
+}
+
+int main() {
+    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
+    int t;
+    cin>>t;
+    
+    while(t--)
+    {
+        lli n;
+        cin>>n;
+        lli large= 0;
+        lli a,b,del;
+        for(a = 999; a > 99; a--)
+        {
+            if(a % 11 == 0)
+            {   
+                b = 999;
+                del = 1;
+            }
+            else
+            {
+                b = 990;
+                del = 11;
+            }    
+
+            while(b>=a)
+            {
+                string s = to_string(a*b);
+                if (a*b <= large)
+                    break;
+
+                if(ispalin(s, 0, s.length()-1))
+                    if(a*b < n)
+                        large = max(a*b,large);
+                    
+                b = b-del;
+                
+            }
+                     
+            
+        }
+        cout<<large<<endl;
+    }
+    return 0;
+}

Project Euler (HackerRank)/005. Smallest multiple.cpp

@@ -0,0 +1,25 @@
+#include <bits/stdc++.h>
+#define lli long long int
+using namespace std;
+
+int main(){
+    int t; 
+    cin>>t;
+    int primes[12] = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37}; 
+    while(t--)
+    {
+        int n;
+        cin>>n;
+        lli answer = 1;
+        for(int i=0; i<12; i++)
+        {
+            int ans = 1;
+            while(ans <= n)
+                ans *= primes[i];
+            ans /= primes[i];
+            answer *= ans;     
+        }
+        cout<<answer<<endl;
+    }
+    return 0;
+}

training-sheet/B/007. Effective Approach.cpp

@@ -0,0 +1,32 @@
+#include <bits/stdc++.h>
+#define lli long long int
+#define endl "\n"
+#define MAX  2005
+using namespace std;
+
+
+int main()
+{
+	int n, data;
+	cin>>n;
+	vector<int>v1(n+1);
+
+	for(int i = 0; i<n; i++)
+	{
+		cin>>data;
+		v1[data] = i+1;
+	}
+
+	lli ansa(0), ansb(0);
+	int q;
+	cin>>q;
+	while(q--)
+	{
+		cin>>data;
+		ansa += v1[data];
+		ansb += (n - v1[data] + 1);
+	} 
+	cout<<ansa<<" "<<ansb;
+
+
+}

training-sheet/B/008. Easter Eggs.cpp

@@ -0,0 +1,19 @@
+#include <bits/stdc++.h>
+#define lli long long int
+#define endl "\n"
+#define MAX  2005
+using namespace std;
+
+
+int main()
+{
+	int n, count = 0, i = 0;
+	cin>>n;
+	string s =  "ROYGBIV";
+	int rep = n/7;
+	int extra = n%7;
+	while(rep--)
+		cout<<s;
+	 string list[7] = {"", "G", "GB", "YGB", "YGBI", "OYGBI" , "OYGBIV"};
+	cout<<list[extra];
+}