diff --git a/C++/bubble_sort.cpp b/C++/bubble_sort.cpp
index b91460c..9d13da8 100644
--- a/C++/bubble_sort.cpp
+++ b/C++/bubble_sort.cpp
@@ -10,19 +10,19 @@ int main()
 	int a[n];
 	cout<<"Enter the array elements: "; 
 	
-	for(i=0;i<n;++i)
+	for(i=0;i<n;i++)
 		cin>>a[i];
 		
-	for(i=1;i<n;++i)
+	for(i=0;i<n-1;++i)
 	{
-		for(j=0;j<(n-i);++j)
+		for(j=n-1;j>i;j--)
 		{
-			if(a[j]>a[j+1])
+			if(a[j]<a[j-1])
 			{
-				k=1;
-				temp=a[j];
-				a[j]=a[j+1];
-				a[j+1]=temp;
+				k=a[j];
+				a[j]=a[j-1];
+				a[j-1]=k;
+				
 			}
 		}
 		if(k==0)
diff --git a/C++/insertionsort.cpp b/C++/insertionsort.cpp
index 8c6fe10..756fc42 100644
--- a/C++/insertionsort.cpp
+++ b/C++/insertionsort.cpp
@@ -1,26 +1,40 @@
-#include <bits/stdc++.h> 
-using namespace std; 
-
-template<typename T>
-void insertionsort(vector<T> &array){
-  int n = array.size();
-
-	for(int i = 1; i < n; i++){
-		for(int j = i; j > 0 and array[j-1] > array[j]; j--){
-			swap(array[j-1], array[j]);
-		}
-	}
+#include <stdio.h>
+
+void insertionSort (int array[], int array_size) {
+    int i, j, k;
+
+    for (i = 1; i < array_size; i++) {
+        k = array[i];
+        j = i - 1;
+
+        while ((j >= 0) && (array[j] > k)) {
+            array[j + 1] = array[j];
+            j--;
+        }
+        array[j + 1] = k;
+    }
+
 }
 
-int main() 
-{ 
-  srand((unsigned int)time(NULL));
-  vector<int> arr;
-  for(int i = 0; i < 10; i++) arr.emplace_back(rand()%1000);
-  insertionsort(arr);
-  for(int i = 0; i < arr.size(); i++){
-    cout << arr[i] << " ";
-  }
-  cout << endl;
-	return 0; 
-} 
+
+int main (void) {
+
+    int i;
+    int array[10] = {3, 6, 1, 7, 2, 0, 4, 5, 9, 8};
+
+    printf("       array: ");
+    for (i = 0; i < sizeof(array) / sizeof(array[0]); i++) {
+        cout << array[i] << ' ';
+    }
+    cout << endl;
+
+    insertionSort(array, sizeof(array) / sizeof(array[0]));
+
+    printf("sorted array: ");
+    for (i = 0; i < sizeof(array) / sizeof(array[0]); i++) {
+ 	cout << array[i] << ' ';
+    }
+    cout << endl;
+
+    return 0;
+}
diff --git a/C++/quicksort.cpp b/C++/quicksort.cpp
index 1a1c268..9261059 100644
--- a/C++/quicksort.cpp
+++ b/C++/quicksort.cpp
@@ -1,38 +1,54 @@
-#include <bits/stdc++.h> 
-using namespace std; 
-
-template<typename T>
-void qsfunc(vector<T> &array, int left, int right){
-  if(left >= right) return;
-  int p = array[left];
-
-  int l = left, r = right;
-  while(1){
-    while(l < right and array[l] < p) l++;
-    while(r > left and array[r] > p) r--;
-    if(l >= r) break;
-    swap(array[l], array[r]);
-  }
-
-  qsfunc(array, left, l-1);
-  qsfunc(array, l+1, right);
+#include <stdio.h>
+
+void swap(int a, int b)
+{
+    int t = a;
+    a = b;
+    b = t;
+}
+
+int partition (int array[], int l, int r) {
+    int pivot = array[r];
+    int i = (l - 1);
+
+    for (int j = l; j <= r - 1; j++) {
+        if (array[j] <= pivot) {
+            i++;
+            swap(&array[i], &array[j]);
+        }
+    }
+    swap(&array[i + 1], &array[r]);
+    return (i + 1);
 }
 
-template<typename T>
-void quicksort(vector<T> &array){
-  int n = array.size();
-  qsfunc(array, 0, n-1);
+void quickSort(int array[], int l, int r) {
+    if (l < r) {
+        int pivot = partition(array, l, r);
+        quickSort(array, l, pivot - 1);
+        quickSort(array, pivot + 1, r);
+    }
 }
 
-int main() 
-{ 
-  srand((unsigned int)time(NULL));
-  vector<int> arr;
-  for(int i = 0; i < 10; i++) arr.emplace_back(rand()%1000);
-  quicksort(arr);
-  for(int i = 0; i < arr.size(); i++){
-    cout << arr[i] << " ";
-  }
-  cout << endl;
-	return 0; 
-} 
+
+
+int main (void) {
+
+    int i;
+    int array[10] = {3, 6, 1, 7, 2, 0, 4, 5, 9, 8};
+
+    printf("       array: ");
+    for (i = 0; i < sizeof(array) / sizeof(array[0]); i++) {
+        cout << array[i] << " ";
+    }
+    cout << endl;
+
+    quickSort(array, 0, sizeof(array) / sizeof(array[0]) - 1);
+
+    printf("sorted array: ");
+    for (i = 0; i < sizeof(array) / sizeof(array[0]); i++) {
+        cout << array[i] << " ";
+    }
+    cout << endl;
+
+    return 0;
+}
diff --git a/C++/selectionsort.cpp b/C++/selectionsort.cpp
index e2b2f64..8f1b3f1 100644
--- a/C++/selectionsort.cpp
+++ b/C++/selectionsort.cpp
@@ -2,11 +2,11 @@
 #include <bits/stdc++.h> 
 using namespace std; 
 
-void swap(int *xp, int *yp) 
+void swap(int xp, int　yp) 
 { 
-	int temp = *xp; 
-	*xp = *yp; 
-	*yp = temp; 
+	int temp = xp; 
+	xp = yp; 
+	yp = temp; 
 } 
 
 void selectionSort(int arr[], int n)