merging

C++/Hashmaps/hashmap.h

@@ -0,0 +1,190 @@
+/*
+ * Copyright 2020 Ujjwal
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include<string>
+#include<stdio.h>
+using namespace std;
+template <class V>
+
+class mapNode{
+  public: 
+  string key;
+  V value;
+  mapNode *next;
+
+  mapNode(string key,V value){
+    this->key = key;
+    this->value = value;
+    next = NULL;
+  }
+
+  ~mapNode(){
+    delete next;
+  }
+};
+
+template <class V>
+class ourmap
+{
+  mapNode<V> **buckets;
+  int count; 
+  int numBuckets;
+
+  public:
+  ourmap(){
+     count = 0;
+    numBuckets = 5;
+    buckets = new mapNode<V> *[numBuckets];
+
+    for (int i = 0; i < numBuckets;i++)
+    {
+      buckets[i] = NULL;
+    }
+  }
+  ~ourmap() {
+    for (int i = 0; i < numBuckets;i++)
+    {
+      delete buckets[i];
+    }
+    delete[] buckets;
+  }
+
+// occupied in bucket array
+int size(){
+  return count;
+}
+
+// get value corresponding to key
+V getValue(string key){
+int bucketIndex = getBucketIndex(key);
+ mapNode<V> *head = buckets[bucketIndex]; 
+ while(head!=NULL)
+ {
+   if(head->key==key)
+     return head->value;
+
+   head = head->next;
+ }
+ return 0;
+}
+
+// hashcode and compression function
+private:
+int getBucketIndex(string key){
+  int hashCode=0;
+
+  int currentCoefficient = 1;
+  for (int i = key.length() - 1; i >= 0;i--)
+  {
+    hashCode += key[i] * currentCoefficient;
+    hashCode = hashCode % numBuckets;
+    currentCoefficient *= 37;
+    currentCoefficient = currentCoefficient % numBuckets;
+  }
+    return hashCode % numBuckets;
+}
+
+// rehashing function
+void rehash(){
+  mapNode<V> **temp = buckets;
+  buckets = new mapNode<V> *[2 * numBuckets];
+  for (int i = 0; i < 2 * numBuckets;i++)
+  {
+    buckets[i] = NULL; 
+  }
+  int oldBucketCount = numBuckets;
+  numBuckets *= 2;
+  count = 0;
+
+  for (int i = 0; i < oldBucketCount;i++)
+  {
+    mapNode<V> *head = temp[i];
+    while(head!=NULL)
+    {
+      string key = head->key;
+      V value = head->value;
+      insert(key, value);
+      head = head->next;
+    }
+  }
+
+  for (int i = 0; i < oldBucketCount;i++)
+  {
+     mapNode<V> *head = temp[i];
+     delete head;
+  }
+  delete[] temp;
+}
+
+public:
+double getLoadFactor(){
+  return (1.0 * count) / numBuckets; 
+}
+
+// inserting element
+void insert(string key, V value){
+  int bucketIndex = getBucketIndex(key);
+  mapNode<V> *head = buckets[bucketIndex]; 
+  while(head!=NULL)
+  {
+    if(head->key==key)
+    {
+      head->value = value;
+      return;
+
+    }
+    head = head->next; 
+  }
+head = buckets[bucketIndex];
+mapNode<V> *node = new mapNode<V>(key, value);
+
+node->next = head;
+buckets[bucketIndex] = node;
+
+count++;
+
+//rehashing
+double loadfactor = (1.0 * count) / numBuckets;
+if(loadfactor>0.7)
+  rehash();
+}
+
+// remove the element
+V remove(string key){
+  int bucketIndex = getBucketIndex(key);
+  mapNode<V> *head = buckets[bucketIndex];
+  mapNode<V> *prev = NULL; 
+
+  while(head!=NULL)
+  {
+    if(head->key==key)
+    { if(prev==NULL)
+        buckets[bucketIndex] = head->next ;
+      else
+        prev->next = head->next;
+
+      V value = head->value;
+      head->next = NULL;
+      delete head;
+      count--;
+      return value;
+    }
+    prev = head;
+    head = head->next;
+  }
+  return 0;
+}
+};

C++/competitive/LeetCode/Best-Time-to-Buy-and-Sell-Stock-II.cpp

@@ -0,0 +1,40 @@
+// Copyright 2020 Avinash Trivedi
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
+class Solution
+{
+	public:
+		int maxProfit(vector<int> &prices)
+		{
+			int sum = 0;
+			//If the number of element in the array are zero or one just return zero.
+			if (prices.size() == 1 or prices.size() == 0)
+			{
+				return 0;
+			}
+
+			//Traverse the array and compare the consecutive two elements .
+			for (int i = 0; i < prices.size() - 1; i++)
+			{
+				// If first consecuitve element is less than second subtract both and add in the sum varibale. 
+				if (prices[i] < prices[i + 1])
+				{
+					sum += prices[i + 1] - prices[i];
+
+				}
+			}
+
+			//Finally return the sum.
+			return sum;
+
+		}
+};

C++/competitive/LeetCode/maximum-subarray.cpp

@@ -0,0 +1,40 @@
+// Copyright 2020  Avinash  Trivedi
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+ class Solution
+ {
+ 	public:
+ 		int maxSubArray(vector<int> &nums)
+ 		{
+ 			int cs = 0;
+ 			int ms = INT_MIN;
+ 			// if size of array is 1 return that elemnt .
+ 			if (nums.size() == 1)
+ 			{
+ 				return nums[0];
+ 			}
+
+ 			//Linearly traverse the array and add to the current sum variable and take maximum .
+ 			for (int i = 0; i < nums.size(); i++)
+ 			{
+ 				cs = cs + nums[i];
+
+ 				ms = max(cs, ms);
+ 				if (cs < 0)
+ 				{
+ 					cs = 0;
+ 				}
+ 			}
+
+ 			return ms;
+ 		}
+ };
+

C++/competitive/SPOJ/CSUMQ-Cumulative-Sum-Query.cpp

@@ -0,0 +1,65 @@
+// Copyright 2020  Avinash  Trivedi
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
+#include <iostream>
+
+
+#include <bits/stdc++.h>
+
+using namespace std;
+#define pb push_back
+#define intt long long
+#define fori(n) for (ll i = 0; i < n; i++)
+#define forj(n) for (ll j = 0; j < n; j++)
+#define vl vector<ll> 
+#define mod 1000000007
+#define mp make_pair
+#define vp vector<pair<int, int>>
+
+ 	int main()
+ 	{   
+
+
+ 		intt n;
+ 		cin >> n;
+ 		intt a[n];
+		//Taking the input array 
+
+ 		for (intt i = 0; i < n; i++)
+ 		{
+ 			cin >> a[i];
+ 		}
+        //The next k lines each contain two numbers x and y which specify a query you must answer.
+
+ 		intt k;
+ 		cin >> k;
+ 		for (intt i = 0; i < k; i++)
+ 		{   //Range of query x,y.
+
+ 			intt x, y;
+ 			cin >> x >> y;
+			//Declared the sum variable
+
+ 			intt sum = 0;
+			//Traverse the array in the range x,y and keep adding the sum of elments which are in between the query range.
+
+ 			for (intt i = x; i <= y; i++)
+ 			{
+ 				sum += a[i];
+ 			}
+            //Finally return the sum of those elements.
+ 			cout << sum << endl;
+ 		}
+
+ 		return 0;
+ 	}
+

C++/search/linear_search.cpp

@@ -0,0 +1,55 @@
+/*
+Copyright [2020] [Kartikey Sharma]
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+#include<bits/stdc++.h>
+using namespace std;
+
+int search(vector<int> v, int find)
+{
+	int l= v.size();
+	for(int i=0; i<l ; i++)
+	{
+		//return the position of the element if found
+		//for multiple occurences, it will only return the position of the first occurence
+		if(find==v[i])
+			return i;
+	}
+	//if not found in the array
+	return -1;
+}
+
+int main()
+{
+	vector<int> v;
+	//array for example is: 1 3 5 2 4 6 7 9 8
+	v.push_back(1);v.push_back(3);v.push_back(5);
+	v.push_back(2);v.push_back(4);v.push_back(6);
+	v.push_back(7);v.push_back(9);v.push_back(8);
+
+	int n;
+	//to search this element
+	cin>>n;
+
+	int l= search(v,n);
+	if(l==-1)
+		cout<<"Not found\n";
+	else
+		cout<<n<<" is found at position "<<l<<endl;
+
+	return 0;
+}
+
+