old stuff: algorithms

1 files changed, 45 insertions, 0 deletions

diff --git a/algorithms/selection_sort.cc b/algorithms/selection_sort.cc
new file mode 100644
index 0000000..1c42a78
--- /dev/null
+++ b/algorithms/selection_sort.cc
@@ -0,0 +1,45 @@
+#include <iostream>
+
+#define N 4
+
+using namespace std;
+
+
+void
+selectionSort(int *A, int n)
+{
+  int i, j, max, maxpos;
+  for (j=n-1; j>0; j--) {
+    /* find max between A[0],....A[j] */
+    max = A[j];
+    maxpos = j;
+    for (i=j-1; i>=0; i--) {
+      if (A[i]>max) {
+        max = A[i];
+        maxpos = i;
+      }
+    }
+    /* swap */
+    A[maxpos] = A[j];
+    A[j] = max;
+  }
+}
+
+
+int
+main (int argc, char * const argv[]) {
+  int A[N] = {3,1,1,2};
+
+  for(unsigned int i=0; i<N; i++) {
+    cout << A[i];
+  }
+  cout << endl << "sorted:" << endl;
+  selectionSort(A, N);
+  for(unsigned int i=0; i<N; i++) {
+    cout << A[i];
+  }
+  cout << endl;
+
+  return 0;
+}
+