Added Sorting algorithm

Algorithms/Graphs/breadth_first_search.cpp

@@ -0,0 +1,63 @@
+//Graph Traversal Algorithm
+//Language Used: C++
+//Breadth First Traversal algorithm to traverse all nodes of a graph considering only one component in graph
+//Output: This algorithm will give nodes visited in breadth first manner and distance of each node from source.
+//author:namanvats
+#include<bits/stdc++.h>
+using namespace std;
+#define MAX5 100010
+#define pb push_back
+int dist[MAX5];
+bool visit[MAX5];
+vector<int> vec[MAX5];
+queue<int> q;
+void bfs(int src)
+{
+    memset(visit,0,sizeof(visit));
+    dist[src]=0;    
+    q.push(src);
+    while(q.size()!=0)
+    {
+        int p=q.front();
+        cout<<p<<" ";
+        q.pop();
+        visit[p]=1;
+        for(int i=0;i<vec[p].size();i++)
+        {
+            if(visit[vec[p][i]]==0)
+            {
+                q.push(vec[p][i]);
+                dist[vec[p][i]]=dist[p]+1;
+                visit[vec[p][i]]=1;
+            }
+        }
+    }
+}
+int main()
+{
+    //Nodes are numbered from 1
+    cout<<"Enter number of Nodes and Edges"<<'\n';
+    int nodes,edges;
+    cin>>nodes>>edges;
+    cout<<"Enter edges between nodes"<<'\n';
+    for(int i=0;i<edges;i++)
+    {
+        //undirected edges
+        int x,y;
+        cin>>x>>y;
+        vec[x].pb(y);
+        vec[y].pb(x);
+    }
+    cout<<"Enter Source node"<<'\n';
+    int src;
+    cin>>src;
+    cout<<"The nodes are:"<<'\n';
+    bfs(src);
+    cout<<'\n';
+    cout<<"Distance of each node starting from source:"<<'\n';
+    for(int i=1;i<=nodes;i++)
+    {
+        cout<<"Distance of node"<<" "<<i<<":"<<" "<<dist[i]<<"\n";
+    }
+return 0;
+}

Algorithms/Searching/binary_searching.cpp

@@ -0,0 +1,44 @@
+// Program to search in an array using binary search
+// Language used: C++
+// Author: ExpressHermes
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int binary_search(int *ar, int low, int high, int key)
+{
+    if(high < low)
+        return -1;
+
+    int mid = low + (high - low) / 2;
+    if(key == ar[mid])
+        return mid;
+    else if(key < ar[mid])
+        return binary_search(ar, low, mid - 1, key);
+    else if(key > ar[mid])
+        return binary_search(ar, mid + 1, high, key);
+
+}
+
+int main()
+{
+    int n, key;
+    cout << "Enter the size of array: ";
+    cin >> n;
+    int ar[n];
+    cout << "Enter the elements: " << endl;
+    for(int i = 0; i < n; i++)
+        cin >> ar[i];
+
+    cout << "Enter the value to be searched: ";
+    cin >> key;    
+
+    int result =  binary_search(ar, 0, n-1, key);
+
+    if(result == -1)
+        cout << "The key is not present in the array" << endl;
+    else
+        cout << "The key is present in array at index: " << result << endl;
+
+
+}

Algorithms/Searching/linear_searching.cpp

@@ -0,0 +1,42 @@
+// Program to search in an array using Linear Search
+// Language used: C++
+// Author: ExpressHermes
+
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int linear_search(int *ar, int n, int key)
+{
+    int found = 0, i;
+    for(i = 0; i < n - 1; i++)
+    {
+        if(ar[i] == key)
+        {
+            found = 1;
+            break;
+        }
+    }
+
+    if(found == 1)
+     cout << "The key is present in the array at index: " << i << endl;
+    else
+     cout << "The key is not present in the array" << endl;
+}
+
+int main()
+{
+    int n, key;
+    cout << "Enter the size of array: ";
+    cin >> n;
+    int ar[n];
+    cout << "Enter the elements: " << endl;
+    for(int i = 0; i < n; i++)
+        cin >> ar[i];
+
+    cout << "Enter the value to be searched: ";
+    cin >> key;    
+
+    linear_search(ar, n, key);
+
+}

Algorithms/Sorting/bubble_sort.cpp

@@ -0,0 +1,47 @@
+// Program to sort an array in ascending order using Binary Sorting
+// Language used: C++
+// Description: In binary sort, we constantly swap the adjacent elements in wrong order
+// Author: ExpressHermes
+
+#include <bits/stdc++.h>
+using namespace std;
+
+void swap(int *a, int *b) 
+{
+    int temp = *b;
+    *b = *a;
+    *a = temp;
+}
+
+void bubble_sort(int *ar, int n) 
+{
+    for(int i = 0; i < n; i++)
+    {
+        for(int j = 0; j < n-i-1; j++)
+        {
+            if(ar[j] > ar[j+1])
+            {
+                // swap elements in the wrong order
+                swap(&ar[j], &ar[j+1]);
+            }
+        }
+
+    }
+}
+
+int main() 
+{
+    int n;
+    cout << "Enter the number of elements: " << endl;
+    cin >> n;
+    int ar[n];
+    cout << "Enter the elements of array: " << endl;
+    for(int i = 0; i < n; i++)
+        cin >> ar[i];
+
+    bubble_sort(ar, n);
+
+    for(int i = 0; i < n; i++)
+        cout << ar[i] << " ";
+        cout << endl;
+}

Algorithms/Sorting/insertion_sort.cpp

@@ -0,0 +1,41 @@
+// Program to sort an array in ascending order using Insertion Sorting
+// Language used: C++
+// Description: In insertion sort, we pick an element a[i] and we 
+//              insert into it's right position in the sorted subarray ar[0] and ar[i-1]
+// Author: ExpressHermes
+
+#include <bits/stdc++.h>
+using namespace std;
+
+void insertion_sort(int *ar, int n) 
+{
+    for (int i = 1; i < n; i++) 
+    {  
+        int value = ar[i];  
+        int j = i - 1;  
+
+        while (j >= 0 && ar[j] > value) 
+        {  
+            ar[j + 1] = ar[j];  
+            j = j - 1;  
+        }  
+        ar[j + 1] = value;  
+    }  
+}
+
+int main() 
+{
+    int n;
+    cout << "Enter the number of elements: " << endl;
+    cin >> n;
+    int ar[n];
+    cout << "Enter the elements of array: " << endl;
+    for(int i = 0; i < n; i++)
+        cin >> ar[i];
+
+    insertion_sort(ar, n);
+
+    for(int i = 0; i < n; i++)
+        cout << ar[i] << " ";
+        cout << endl;
+}

Algorithms/Sorting/quick_sort.cpp

@@ -0,0 +1,51 @@
+// Program to sort an array in descending order using Quick Sort
+// Language used: C++
+// Description: Quick Sort works on Divide and Conquer algorithm. In this we take a pivot and partition the 
+//              whole array around this pivot. We put the pivot at correct elements at correct position and
+//              put all the smaller elements(smaller than pivot) after the pivot and all the greater elements 
+//              before the pivot. 
+// Author: ExpressHermes
+
+#include <bits/stdc++.h>
+using namespace std;
+
+void quick_sort(int *ar, int n) 
+{
+    if(n < 2)
+        return;
+
+    int pivot = ar[n/2];
+    int i, j;
+    for(i = 0, j = n - 1; ;i++, j--)
+    {
+        while(ar[i] > ar[pivot]) i++;
+        while(ar[j] < ar[pivot]) j--;
+
+        if(i >= j)
+         break;
+
+        int temp = ar[i];
+        ar[i] = ar[j];
+        ar[j] = temp;
+    }
+
+    quick_sort(ar, i);
+    quick_sort(ar + i, n - i);
+}
+
+int main() 
+{
+    int n;
+    cout << "Enter the number of elements: " << endl;
+    cin >> n;
+    int ar[n];
+    cout << "Enter the elements of array: " << endl;
+    for(int i = 0; i < n; i++)
+        cin >> ar[i];
+
+    quick_sort(ar, n);
+
+    for(int i = 0; i < n; i++)
+        cout << ar[i] << " ";
+        cout << endl;
+}

Algorithms/Sorting/selection_sort.cpp

@@ -0,0 +1,48 @@
+// Program to sort an array in ascending order using Selection Sorting
+// Language used: C++
+// Description: In every iteration of selection sort, the minimum element (considering ascending order) 
+//              from the unsorted subarray is picked and moved to the sorted subarray.
+// Author: ExpressHermes
+
+#include <bits/stdc++.h>
+using namespace std;
+
+void swap(int *a, int *b) 
+{
+    int temp = *b;
+    *b = *a;
+    *a = temp;
+}
+
+void selection_sort(int *ar, int n) 
+{
+    for(int i = 0; i < n; i++)
+    {
+        int min_index = i;
+        for(int j = i + 1; j < n; j++)
+        {
+            if(ar[j] < ar[min_index])
+                min_index = j;
+        }
+
+        // place the element in it's right position
+        swap(&ar[i], &ar[min_index]);
+    }
+}
+
+int main() 
+{
+    int n;
+    cout << "Enter the number of elements: " << endl;
+    cin >> n;
+    int ar[n];
+    cout << "Enter the elements of array: " << endl;
+    for(int i = 0; i < n; i++)
+        cin >> ar[i];
+
+    selection_sort(ar, n);
+
+    for(int i = 0; i < n; i++)
+        cout << ar[i] << " ";
+        cout << endl;
+}

README.md

@@ -3,3 +3,6 @@ This is a library of various algorithms that are used in competitive programming
 
 ### sample algorithm
 [disjoint_set_union.cpp](Algorithms/disjoint_set_union/disjoint_set_union.cpp)
+
+
+READ instructions before making any pull request.