add basic implementation

sorting.cpp

+#include<iostream>
+#include "sorting.h"
+using namespace std;
+
+vector<int> sort_custom(vector<int> v1){
+   int i, j;
+   int n=v1.size();
+   for (i = 0; i < n-1; i++) {   
+       for (j = 0; j < n-i-1; j++){ 
+           if (v1[j] > v1[j+1])
+              swap(v1[j], v1[j+1]);
+        }
+    }
+    return v1;    
+}
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