Merge pull request kelvins#245 from andersonhsporto/c-timsort

Add timsort implementation in ANSCI C

Author: kelvins

README.md

@@ -3261,8 +3261,8 @@ In order to achieve greater coverage and encourage more people to contribute to
         <tr>
             <td><a href="https://en.wikipedia.org/wiki/Timsort">Timsort</a></td>
             <td> <!-- C -->
-                <a href="./CONTRIBUTING.md">
-                    <img align="center" height="25" src="./logos/github.svg" />
+                <a href="./src/c/Timsort.c">
+                    <img align="center" height="25" src="./logos/c.svg" />
                 </a>
             </td>
             <td> <!-- C++ -->

src/c/Timsort.c

@@ -0,0 +1,128 @@
+#include <stdio.h>
+
+const int THRESHOLD = 32;
+
+int is_odd(int n) {
+    return n & 1;
+}
+
+int get_fmin(int a, int b) {
+    if (a < b) {
+        return a;
+    }
+    return b;
+}
+
+int get_floor(int n) {
+    return n / 2;
+}
+
+void print_array(int array[], int size) {
+    printf("[");
+    for (int i = 0; i < size; i++) {
+        printf("%d", array[i]);
+        if (i != size - 1) {
+            printf(", ");
+        }
+    }
+    printf("]\n");
+}
+
+int get_run_length(int size_of_array) {
+    int run_length = size_of_array;
+    int remainder = 0;
+
+    while (run_length >= THRESHOLD) {
+        if (is_odd(run_length)) {
+            remainder = 1;
+        }
+        run_length = get_floor(run_length / 2);
+    }
+    return run_length + remainder;
+}
+
+void insertion_sort(int array[], int left_index, int right_index) {
+    for (int i = left_index + 1; i <= right_index; i++) {
+        int temp = array[i];
+        int j = i - 1;
+        while (j >= left_index && array[j] > temp) {
+            array[j + 1] = array[j];
+            j--;
+        }
+        array[j + 1] = temp;
+    }
+}
+
+void merge_runs(int array[], int left_index, int middle_index, int right_index) {
+    int left_size = middle_index - left_index + 1;
+    int right_size = right_index - middle_index;
+    int left[left_size];
+    int right[right_size];
+
+    for (int i = 0; i < left_size; i++) {
+        left[i] = array[left_index + i];
+    }
+    for (int j = 0; j < right_size; j++) {
+        right[j] = array[middle_index + 1 + j];
+    }
+
+    int i = 0;
+    int j = 0;
+    int k = left_index;
+
+    while (i < left_size && j < right_size) {
+        if (left[i] <= right[j]) {
+            array[k] = left[i];
+            i++;
+        } else {
+            array[k] = right[j];
+            j++;
+        }
+        k++;
+    }
+
+    while (i < left_size) {
+        array[k] = left[i];
+        i++;
+        k++;
+    }
+
+    while (j < right_size) {
+        array[k] = right[j];
+        j++;
+        k++;
+    }
+}
+
+void timsort(int array[], int size) {
+    int run_length = get_run_length(size);
+
+    for (int i = 0; i < size; i += run_length) {
+        insertion_sort(array, i, get_fmin((i + run_length - 1), (size - 1)));
+    }
+
+    for (int size_of_run = run_length; size_of_run < size; size_of_run *= 2) {
+        for (int left_index = 0; left_index < size; left_index += 2 * size_of_run) {
+            int middle_index = left_index + size_of_run - 1;
+            int right_index = get_fmin((left_index + 2 * size_of_run - 1), (size - 1));
+            merge_runs(array, left_index, middle_index, right_index);
+        }
+    }
+}
+
+int main() {
+    int array[] = { 5, 2, -2147483648, 1, 4, 5323, -1, 0, 10, 9, 8, 7, 6, 2147483647, 4, 3, 2 };
+    int size = sizeof(array) / sizeof(array[0]);
+
+    printf("Original array:\t");
+    print_array(array, size);
+
+    timsort(array, size);
+
+    printf("Sorted array:\t");
+    print_array(array, size);
+    return 0;
+}
+
+
+