feat: add C code in chapter_greedy (#755)

* add fractional_knapsack.c

* update CMakeLists

* add c code in chapter_greedy

* fix header format

* format code by clang-format

* remove extra comments

* replace ternary operator to MACRO

* parameters form adjustment

* Update fractional_knapsack.c

* Update max_capacity.c

* Update max_product_cutting.c

* add comments for consistency with cpp ver

* move MIN&MAX macro to source file

* typo fix

---------

Co-authored-by: Yudong Jin <krahets@163.com>

codes/c/chapter_greedy/max_product_cutting.c

@@ -0,0 +1,38 @@
+/**
+ * File: max_product_cutting.c
+ * Created Time: 2023-09-15
+ * Author: xianii (xianyi.xia@outlook.com)
+ */
+
+#include "../utils/common.h"
+
+/* 最大切分乘积：贪心 */
+int maxProductCutting(int n) {
+    // 当 n <= 3 时，必须切分出一个 1
+    if (n <= 3) {
+        return 1 * (n - 1);
+    }
+    // 贪心地切分出 3 ，a 为 3 的个数，b 为余数
+    int a = n / 3;
+    int b = n % 3;
+    if (b == 1) {
+        // 当余数为 1 时，将一对 1 * 3 转化为 2 * 2
+        return pow(3, a - 1) * 2 * 2;
+    }
+    if (b == 2) {
+        // 当余数为 2 时，不做处理
+        return pow(3, a) * 2;
+    }
+    // 当余数为 0 时，不做处理
+    return pow(3, a);
+}
+
+/* Driver Code */
+int main(void) {
+    int n = 58;
+    // 贪心算法
+    int res = maxProductCutting(n);
+    printf("最大切分乘积为 %d\n", res);
+
+    return 0;
+}