Add couting sort

1 files changed, 86 insertions, 0 deletions

diff --git a/Year_2/Algorithms/data_structures/counting_sort.cc b/Year_2/Algorithms/data_structures/counting_sort.cc
new file mode 100644
index 0000000..71cb505
--- /dev/null
+++ b/Year_2/Algorithms/data_structures/counting_sort.cc
@@ -0,0 +1,86 @@
+#include <fstream>
+#include <iostream>
+#include <string.h>
+#include <string>
+
+using namespace std;
+
+void
+counting_sort(int* A, size_t n)
+{
+    int i, j;
+    int max, min;
+    int* freq;
+    int* t;
+    int range;
+
+    max = A[0], min = A[0];
+    t = new int[n];
+
+    for (i = 1; i < n; ++i) {
+        if (A[i] > max)
+            max = A[i];
+
+        if (A[i] < min)
+            min = A[i];
+    }
+
+    range = (max - min) + 1;
+
+    freq = new int[range];
+
+    for (i = 0; i < range; ++i) {
+        freq[i] = 0;
+    }
+
+    for (i = 0; i < n; ++i) {
+        freq[A[i] - min] += 1;
+    }
+    for (i = 1; i < range; ++i) {
+        freq[i] = freq[i] + freq[i - 1];
+    }
+
+    for (i = n - 1; i >= 0; --i) {
+        t[freq[A[i] - min] - 1] = A[i];
+        freq[A[i] - min]--;
+    }
+
+    for (i = 0; i < n; ++i)
+        A[i] = t[i];
+
+    delete[] freq;
+    delete[] t;
+}
+
+int
+main()
+{
+    ifstream fin("input.txt");
+    ofstream fout("output.txt");
+    string s;
+
+    int* A = new int[1024];
+    int n;
+    char* token;
+
+    for (int i = 0; i < 100; ++i) {
+        getline(fin, s);
+        n = 0;
+        token = strtok((char*)s.c_str(), " ");
+        while (token) {
+            A[n++] = atoi(token);
+            token = strtok(NULL, " ");
+        }
+
+        counting_sort(A, n);
+
+        for (int i = 0; i < n - 1; ++i) {
+            fout << A[i] << ' ';
+        }
+        fout << A[n - 1] << endl;
+    }
+
+    delete[] A;
+
+    return 0;
+}