Init commit: Combine all COD projects to one repo

Q3-qsort/src/main.c

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+//============================================================================
+// Name        : quiz3.cpp
+// Author      : Christos Choutouridis
+// Version     :
+// Copyright   : Your copyright notice
+// Description : Hello World in C++, Ansi-style
+//============================================================================
+
+
+
+int v[] = {
+	3, 10, 8, 2, 7, 1, 5, 9, 6, 4
+};
+
+
+void swap (int i, int j) {
+	int t = v[i];
+	v[i] = v[j];
+	v[j] = t;
+}
+
+// partition(int f, int l) : permutes the values in vector v[]
+//   between positions f and l, using as pivot the element v[l], such
+//   that
+//     f <= i < p ==> v[i] <= v[p]
+//     p < i <= l ==> v[p] <  v[i]
+//   The function returns the position p of the pivot.
+int partition(int f, int l) {
+	int pivot = v[l];       	// element v[l] is the pivot
+	int i = f;                  // i points to the beginning of the vector
+
+	// loop over vector
+	for (int j = f; j < l; j++)
+		if (v[j] < pivot)       // element smaller than pivot
+			swap(i++,j);        // swap it with position pointed by i
+
+	swap(i, l );                // swap pivot to its correct position
+	return (i);                 // return pivot's position
+}
+
+// qsort(int f, int l) : sorts the elements of v[] between positions f:l
+void qsort(int f, int l) {
+	int pivot;
+	if (f < l) {
+		pivot = partition(f, l);
+
+		qsort(f, pivot - 1);  	// Before pi
+		qsort(pivot + 1, l); 	// After pi
+	}
+}
+
+
+int main() {
+	int n = 10;
+
+	qsort (0, 9);
+	return 0;
+}