change implementation to insertion-sort

sorting.cpp

 #include "sorting.h"
 #include<iostream>
+
 vector<int> sort_custom(vector<int> inp){
-	for (int i=0;i<inp.size();i++){
-		for (int j=1;j<inp.size();j++){
-			if (inp[j-1]>inp[j]){
-				int temp=inp[j];
-				inp[j]=inp[j-1];
-				inp[j-1]=temp;
-				}
-			}
-		}
-	return inp;
-}
\ No newline at end of file
+	int i, key, j;
+   for (i = 1; i < inp.size(); i++)
+   {
+       key = inp[i];
+       j = i-1;
+       while (j >= 0 && inp[j] > key)
+       {
+           inp[j+1] = inp[j];
+           j = j-1;
+       }
+       inp[j+1] = key;
+   }
+   return inp;
+}
+
+ 
\ No newline at end of file