DSA in C++

README.md

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+# Data Structures
+
+
+
+
+This is a repository containing various C++ Programs to understand the basic concepts of Data Structures and Algorithms.
+

Sorting Programs/bubble_sort.cpp

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+#include <iostream>
+using namespace std;
+void Bubblesort(int A[],int N)
+{
+    int i,j,t;
+    for(i=0;i<=N-2;i++)
+        for(j=0;j<=N-2-i;j++)
+        if(A[j]>A[j+1])
+        {
+            t=A[j];
+            A[j]=A[j+1];
+            A[j+1]=t;
+        }
+}
+int main()
+{
+    int A[200],N,i;
+    cout<<"Enter no. of elements to be taken: ";
+    cin>>N;
+    cout<<"Enter the elements of array: "<<endl;
+    for(i=0;i<N;i++)
+        cin>>A[i];
+        Bubblesort(A,N);
+        cout<<"Sorted array: "<<endl;
+        for(i=0;i<N;i++)
+            cout<<A[i]<<" ";
+    return 0;
+}

Sorting Programs/insertion_sort.cpp

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+#include <iostream>
+using namespace std;
+void Insertionsort(int A[],int N)
+{
+    int i,j,t;
+    for(i=1;i<=N-1;i++)
+    {
+        t=A[i];
+        j=i-1;
+        while(t<A[j]&&j>=0)
+        {
+            A[j+1]=A[j];
+            j--;
+        }
+        A[j+1]=t;
+    }
+}
+int main()
+{
+    int A[200],N,i;
+    cout<<"Enter total no. of elements to be sorted: ";
+    cin>>N;
+    cout<<"Enter the elements of array: "<<endl;
+    for(i=0;i<N;i++)
+        cin>>A[i];
+        Insertionsort(A,N);
+        cout<<"Sorted array: "<<endl;
+        for(i=0;i<N;i++)
+            cout<<A[i]<<" ";
+    return 0;
+}

Sorting Programs/merge_sort.cpp

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+#include <iostream>
+using namespace std;
+void merging(int A[],int l,int m,int r)
+{
+    int i,j,k,n1,n2;
+    n1=m-l+1;
+    n2=r-m;
+    int L[n1],R[n2];
+    for(i=0;i<n1;i++)
+        L[i]=A[l+i];
+    for(j=0;j<n2;j++)
+        R[j]=A[m+1+j];
+    i=0;
+    j=0;
+    k=l;
+    while(i<n1&&j<n2)
+    {
+        if(L[i]<=R[j])
+        {
+            A[k]=L[i];
+            i++;
+        }
+        else
+        {
+            A[k]=R[j];
+            j++;
+        }
+        k++;
+    }
+    while(i<n1)
+    {
+        A[k]=L[i];
+        i++;
+        k++;
+    }
+    while(j<n2)
+    {
+        A[k]=R[j];
+        j++;
+        k++;
+    }
+}
+void mergesort(int A[],int l,int r)
+{
+    if(l<r)
+    {
+        //Same as (l+r)/2, but avoids overflow for large l and h
+        int m=l+(r-l)/2;
+        mergesort(A,l,m);
+        mergesort(A,m+1,r);
+        merging(A,l,m,r);
+    }
+}
+int main()
+{
+    int A[200],N,i;
+    cout<<"Enter total no. of elements to be sorted: ";
+    cin>>N;
+    cout<<"Enter the elements of array: "<<endl;
+    for(i=0;i<N;i++)
+        cin>>A[i];
+    mergesort(A,0,N-1);
+    cout<<"Sorted array: "<<endl;
+    for(i=0;i<N;i++)
+        cout<<A[i]<<" ";
+    return 0;
+}

Sorting Programs/quick_sort.cpp

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+#include <iostream>
+using namespace std;
+void swap1(int &a,int &b)
+{
+    int t;
+    t=a;
+    a=b;
+    b=t;
+}
+int partition1(int A[],int l,int h)
+{
+    int pivot=A[h];
+    int i=l-1;
+    for(int j=l;j<=h-1;j++)
+    {
+        if(A[j]<=pivot)
+        {
+            i++;
+            swap1(A[i],A[j]);
+        }
+    }
+    swap1(A[i+1],A[h]);
+    return (i+1);
+}
+void quicksort(int A[],int l,int h)
+{
+    if(l<h)
+    {
+        int p=partition1(A,l,h);
+        quicksort(A,l,p-1);
+        quicksort(A,p+1,h);
+    }
+}
+int main()
+{
+    int A[200],N,i;
+    cout<<"Enter total no. of elements to be sorted: ";
+    cin>>N;
+    cout<<"Enter the elements of array: "<<endl;
+    for(i=0;i<N;i++)
+        cin>>A[i];
+    quicksort(A,0,N-1);
+    cout<<"Sorted array: "<<endl;
+    for(i=0;i<N;i++)
+        cout<<A[i]<<" ";
+    return 0;
+}

Sorting Programs/selection_sort.cpp

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+#include <iostream>
+using namespace std;
+void Selectionsort(int A[],int n)
+{
+    int i,j,small,pos,temp;
+    for(i=0;i<=n-2;i++)
+    {
+        small=A[i];
+        pos=i;
+        for(j=i+1;j<=n-1;j++)
+        if(A[j]<small)
+        {
+            small=A[j];
+            pos=j;
+        }
+        temp=A[i];
+        A[i]=A[pos];
+        A[pos]=temp;
+    }
+}
+int main()
+{
+    int A[200],N,i;
+    cout<<"Enter total no. of elements to be sorted: ";
+    cin>>N;
+    cout<<"Enter the elements of array: "<<endl;
+    for(i=0;i<N;i++)
+        cin>>A[i];
+    Selectionsort(A,N);
+    cout<<"Sorted array: "<<endl;
+    for(i=0;i<N;i++)
+        cout<<A[i]<<" ";
+    return 0;
+}