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-rw-r--r--1_anno/Programmazione_2/algorithms/quicksort.cc38
1 files changed, 38 insertions, 0 deletions
diff --git a/1_anno/Programmazione_2/algorithms/quicksort.cc b/1_anno/Programmazione_2/algorithms/quicksort.cc
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+++ b/1_anno/Programmazione_2/algorithms/quicksort.cc
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+#include<iostream>
+
+using namespace std;
+
+int partition(int A[], int l, int r) {
+ int x = A[r];
+ int i = l-1;
+
+ for(int j = l; j < r; ++j) {
+ if(A[j] <= x) {
+ swap(A[++i], A[j]);
+ }
+ }
+ swap(A[++i], A[r]);
+ return i;
+}
+
+void quicksort(int A[], int l, int r) {
+ if(l < r) {
+ int q = partition(A, l, r);
+ quicksort(A, l, q-1);
+ quicksort(A, q+1, r);
+ }
+}
+
+int main() {
+ int a[] = {7,1,22,3,2,12,27,31,6};
+ for(int i = 0; i < 9; ++i) {
+ cout << a[i] << ' ';
+ }
+ cout << endl;
+ quicksort(a, 0, 8);
+ for(int i = 0; i < 9; ++i) {
+ cout << a[i] << ' ';
+ }
+
+ return 0;
+}