Solved Day 1 Problem

DSA Marathon/Day 1/Solution/suveshmoza.cpp

@@ -0,0 +1,39 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int findDuplicate(int arr[])
+{
+
+    int slow = arr[0];
+    int fast = arr[arr[0]];
+
+    while (slow != fast)
+    {
+        slow = arr[slow];
+        fast = arr[arr[fast]];
+    }
+
+    fast = 0;
+
+    while (slow != fast)
+    {
+
+        slow = arr[slow];
+        fast = arr[fast];
+    }
+
+    return fast;
+}
+
+int main()
+{
+    int a[] = {1, 3, 4, 2, 2};
+    int b[] = {3, 1, 3, 4, 2};
+    int c[] = {1, 1};
+    int d[] = {1, 1, 2};
+    cout << findDuplicate(a) << endl;
+    cout << findDuplicate(b) << endl;
+    cout << findDuplicate(c) << endl;
+    cout << findDuplicate(d) << endl;
+    return 0;
+}

DSA Marathon/Day 10/Solution/suveshmoza.cpp

@@ -0,0 +1,22 @@
+bool isInputValid(string s)
+{
+    stack<char> st;
+    int n = s.size();
+    for (int i = 0; i < n; i++)
+    {
+        if (s[i] == '[' || s[i] == '(' || s[i] == '{')
+            st.push(s[i]);
+        else if (!st.empty() && s[i] == ')' && st.top() == '(')
+            st.pop();
+        else if (!st.empty() && s[i] == '}' && st.top() == '{')
+            st.pop();
+        else if (!st.empty() && s[i] == ']' && st.top() == '[')
+            st.pop();
+        else
+            st.push(s[i]);
+    }
+
+    if (st.empty())
+        return true;
+    return false;
+}

DSA Marathon/Day 11/Solution/suveshmoza.cpp

@@ -0,0 +1,34 @@
+#include<iostream>
+#include <stack>
+using namespace std;
+
+int performOperation(char c,int op1,int op2){
+    if(c=='+') return op1+op2;
+    else if(c=='-') return op1-op2;
+    else if(c=='*') return op1*op2;
+    else return op1/op2;
+}
+
+int main()
+ {
+	int t;
+	cin>>t;
+	while(t--){
+	    string s;
+	    stack<int>st;
+	    cin>>s;
+	    for(int i=0;i<s.length();i++){
+	        if(isdigit(s[i])) st.push((s[i]-'0'));
+	        else{
+	            int op2=st.top();
+	            st.pop();
+	            int op1=st.top();
+	            st.pop();
+	            int res=performOperation(s[i],op1,op2);
+	            st.push(res);
+	        }
+	    }
+	    cout<<(st.top())<<endl;
+	}
+	return 0;
+}

DSA Marathon/Day 12/Solution/suveshmoza.cpp

@@ -0,0 +1,38 @@
+int celebrity(vector<vector<int>> M, int n)
+{
+    stack<int> s;
+    for (int i = 0; i < n; i++)
+    {
+        s.push(i);
+    }
+    while (s.size() >= 2)
+    {
+        int i = s.top();
+        s.pop();
+        int j = s.top();
+        s.pop();
+
+        if (M[i][j] == 1)
+        {
+            s.push(j);
+        }
+        else
+        {
+            s.push(i);
+        }
+    }
+    int pot = s.top();
+    s.pop();
+
+    for (int i = 0; i < n; i++)
+    {
+        if (i != pot)
+        {
+            if (M[i][pot] == 0 || M[pot][i] == 1)
+            {
+                return -1;
+            }
+        }
+    }
+    return pot;
+}

DSA Marathon/Day 13/Solution/suveshmoza.cpp

@@ -0,0 +1,101 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+struct Queue
+{
+	int front, rear, capacity;
+	int *queue;
+	Queue(int c)
+	{
+		front = rear = 0;
+		capacity = c;
+		queue = new int;
+	}
+
+	~Queue() { delete[] queue; }
+	void push(int data)
+	{
+		if (capacity == rear)
+		{
+			return;
+		}
+		else
+		{
+			queue[rear] = data;
+			rear++;
+		}
+		return;
+	}
+	void pop()
+	{
+		if (front == rear)
+		{
+			return;
+		}
+		else
+		{
+			for (int i = 0; i < rear - 1; i++)
+			{
+				queue[i] = queue[i + 1];
+			}
+			rear--;
+		}
+		return;
+	}
+	void display()
+	{
+		int i;
+		if (front == rear)
+		{
+			return;
+		}
+		for (i = front; i < rear; i++)
+		{
+			cout << queue[i] << " ";
+		}
+		cout << endl;
+		return;
+	}
+
+	int checkFrequency(int x)
+	{
+		int freq = 0;
+		for (int i = front; i <= rear; i++)
+		{
+			if (queue[i] == x)
+			{
+				freq++;
+			}
+		}
+		if (freq == 0)
+			return -1;
+		return freq;
+	}
+};
+
+// Driver code
+int main()
+{
+	int size;
+	cin >> size;
+	Queue q(size);
+
+	for (int i = 0; i < size; i++)
+	{
+		int key;
+		cin >> key;
+		q.push(key);
+	}
+	int n;
+	cin >> n;
+	int arr[n];
+	for (int i = 0; i < n; i++)
+	{
+		cin >> arr[i];
+	}
+	for (int i = 0; i < n; i++)
+	{
+		cout << q.checkFrequency(arr[i]) << endl;
+	}
+	return 0;
+}

DSA Marathon/Day 14/Solution/suveshmoza.cpp

@@ -0,0 +1,90 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+struct Queue
+{
+    int front, rear, capacity;
+    int *queue;
+    Queue(int c)
+    {
+        front = rear = 0;
+        capacity = c;
+        queue = new int;
+    }
+
+    ~Queue() { delete[] queue; }
+    void push(int data)
+    {
+        if (capacity == rear)
+        {
+            return;
+        }
+        else
+        {
+            queue[rear] = data;
+            rear++;
+        }
+        return;
+    }
+    void pop()
+    {
+        if (front == rear)
+        {
+            return;
+        }
+        else
+        {
+            for (int i = 0; i < rear - 1; i++)
+            {
+                queue[i] = queue[i + 1];
+            }
+            rear--;
+        }
+        return;
+    }
+    void display()
+    {
+        int i;
+        if (front == rear)
+        {
+            return;
+        }
+        for (i = front; i < rear; i++)
+        {
+            cout << queue[i] << " ";
+        }
+        cout << endl;
+        return;
+    }
+
+    void reverse()
+    {
+        int i = front, j = rear - 1;
+        while (i < j)
+        {
+            swap(queue[i++], queue[j--]);
+        }
+    }
+};
+
+int main()
+{
+    int t;
+    cin >> t;
+    while (t--)
+    {
+        int size;
+        cin >> size;
+        Queue q(size);
+
+        for (int i = 0; i < size; i++)
+        {
+            int key;
+            cin >> key;
+            q.push(key);
+        }
+        q.reverse();
+        q.display();
+    }
+    return 0;
+}

DSA Marathon/Day 15/Solution/suveshmoza.cpp

@@ -0,0 +1,30 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+void generateBinaryNumbers(int n)
+{
+    queue<string> q;
+    q.push("1");
+    while (n--)
+    {
+        string S = q.front();
+        cout << S << " ";
+        q.pop();
+        q.push(S + "0");
+        q.push(S + "1");
+    }
+}
+
+int main()
+{
+    int t;
+    cin >> t;
+    while (t--)
+    {
+        int n;
+        cin >> n;
+        generateBinaryNumbers(n);
+        cout << endl;
+    }
+    return 0;
+}