Create a pigeon_sort

sorting-algos/pigeon_sort

@@ -0,0 +1,58 @@
+#include<bits/stdc++.h>
+using namespace std;
+void pigeonhole(int a[],int n)
+{
+    int min=a[0],max=a[0],i;     //initialise the value minimum and maximum equal to first element of the array
+    for(i=1;i<n;i++)
+    {
+        if(max<a[i])
+            max=a[i];           //here we find the maximum value of array and store in max
+        if(min>a[i])
+            min=a[i];       //here we find the minimum value of the array and store in min
+    }
+    int range=max-min+1;  //we define a size of holes
+
+    vector<int>holes[range]; // here we initialise a array
+
+    for(int i=0;i<n;i++)
+    {
+    holes[a[i]-min].push_back(a[i]);   //here we sorted the array and store in the holes array
+    }
+    int index=0;
+   for(int i=0;i<range;i++)
+      {
+        vector<int>::iterator it;
+        for(it=holes[i].begin();it!=holes[i].end();++it)
+        {
+            a[index++]= *it;     // here we store the vlue of holes array into a array
+        }
+    }
+}
+int main()
+{
+    int n;
+    cout<<"enter the n";
+    cin>>n;     //we take a array size input from the user
+    int a[n],i;
+    for(i=0;i<n;i++)
+    {
+     cin>>a[i];    // initialise the array
+    }
+     pigeonhole(a,n);   //call the function
+     for(i=0;i<n;i++)
+     {
+      cout<<"the sorted array is"<<endl;   
+      cout<<a[i]<<" ";
+     }
+    return 0;
+}
+
+
+
+/* Input 
+enter the size of n   
+   7 
+   6 4  5 3  2 1 
+the sorted array is
+   1 2 3 4 5 6
+*/