diff --git a/codes/c/chapter_computational_complexity/time_complexity.c b/codes/c/chapter_computational_complexity/time_complexity.c
new file mode 100644
index 00000000..8df06a75
--- /dev/null
+++ b/codes/c/chapter_computational_complexity/time_complexity.c
@@ -0,0 +1,175 @@
+/*
+ * File: time_complexity.c
+ * Created Time: 2023-01-03
+ * Author: sjinzh (sjinzh@gmail.com)
+ */
+
+#include "../include/include.h"
+
+/* 常数阶 */
+int constant(int n) {
+    int count = 0;
+    int size = 100000;
+    int i = 0;
+    for (int i = 0; i < size; i++) {
+        count ++;
+    }
+    return count;
+}
+
+/* 线性阶 */
+int linear(int n) {
+    int count = 0;
+    for (int i = 0; i < n; i++) {
+        count ++;
+    }
+    return count;
+}
+
+/* 线性阶（遍历数组） */
+int arrayTraversal(int *nums, int n) {
+    int count = 0;
+    // 循环次数与数组长度成正比
+    for (int i = 0; i < n; i++) {
+        count ++;
+    }
+    return count;
+}
+
+/* 平方阶 */
+int quadratic(int n) 
+{
+    int count = 0;
+    // 循环次数与数组长度成平方关系
+    for (int i = 0; i < n; i++) {
+        for (int j = 0; j < n; j++) {
+            count ++;
+        }
+    }
+    return count;
+}
+
+/* 平方阶（冒泡排序） */
+int bubbleSort(int *nums, int n) {
+    int count = 0;  // 计数器 
+    // 外循环：待排序元素数量为 n-1, n-2, ..., 1
+    for (int i = n - 1; i > 0; i--) {
+        // 内循环：冒泡操作
+        for (int j = 0; j < i; j++) {
+            // 交换 nums[j] 与 nums[j + 1]
+            int tmp = nums[j];
+            nums[j] = nums[j + 1];
+            nums[j + 1] = tmp;
+            count += 3;  // 元素交换包含 3 个单元操作
+        }
+    }
+    return count;
+}
+
+/* 指数阶（循环实现） */
+int exponential(int n) {
+    int count = 0;
+    int bas = 1;
+    // cell 每轮一分为二，形成数列 1, 2, 4, 8, ..., 2^(n-1)
+    for (int i = 0; i < n; i++) {
+        for (int j = 0; j < bas; j++) {
+            count++;
+        }
+        bas *= 2;
+    }
+    // count = 1 + 2 + 4 + 8 + .. + 2^(n-1) = 2^n - 1
+    return count;
+}
+
+/* 指数阶（递归实现） */
+int expRecur(int n) {
+    if (n == 1) return 1;
+    return expRecur(n - 1) + expRecur(n - 1) + 1;
+}
+
+/* 对数阶（循环实现） */
+int logarithmic(float n) {
+    int count = 0;
+    while (n > 1) {
+        n = n / 2;
+        count++;
+    }
+    return count;
+}
+
+/* 对数阶（递归实现） */
+int logRecur(float n) {
+    if (n <= 1) return 0;
+    return logRecur(n / 2) + 1;
+}
+
+/* 线性对数阶 */
+int linearLogRecur(float n) {
+    if (n <= 1) return 1;
+    int count = linearLogRecur(n / 2) +
+                linearLogRecur(n / 2);
+    for (int i = 0; i < n; i++) {
+        count ++;
+    }
+    return count;
+}
+
+/* 阶乘阶（递归实现） */
+int factorialRecur(int n) {
+    if (n == 0) return 1;
+    int count = 0;
+    for (int i = 0; i < n; i++) {
+        count += factorialRecur(n - 1);
+    }
+    return count;
+}
+
+/* Driver Code */
+int main(int argc, char *argv[]) {
+    // 可以修改 n 运行，体会一下各种复杂度的操作数量变化趋势
+    int n = 8;
+    printf("输入数据大小 n = %d\n", n);
+
+    int count = constant(n);
+    printf("常数阶的计算操作数量 = %d\n", count);
+
+    count = linear(n);
+    printf("线性阶的计算操作数量 = %d\n", count);
+    // 分配堆区内存（创建一维可变长数组：数组中元素数量为n，元素类型为int）
+    int *nums = (int *)malloc(n * sizeof(int));
+    count = arrayTraversal(nums, n);
+    printf("线性阶（遍历数组）的计算操作数量 = %d\n", count);
+
+    count = quadratic(n);
+    printf("平方阶的计算操作数量 = %d\n", count);
+    for (int i = 0; i < n; i++) {
+        nums[i] = n - i;    // [n,n-1,...,2,1]
+    }
+    count = bubbleSort(nums, n);
+    printf("平方阶（冒泡排序）的计算操作数量 = %d\n", count);
+
+    count = exponential(n);
+    printf("指数阶（循环实现）的计算操作数量 = %d\n", count);
+    count = expRecur(n);
+    printf("指数阶（递归实现）的计算操作数量 = %d\n", count);
+
+    count = logarithmic(n);
+    printf("对数阶（循环实现）的计算操作数量 = %d\n", count);
+    count = logRecur(n);
+    printf("对数阶（递归实现）的计算操作数量 = %d\n", count);
+
+    count = linearLogRecur(n);
+    printf("线性对数阶（递归实现）的计算操作数量 = %d\n", count);
+
+    count = factorialRecur(n);
+    printf("阶乘阶（递归实现）的计算操作数量 = %d\n", count);
+
+    // 释放堆区内存
+    if (nums != NULL) {
+        free(nums);
+        nums = NULL;
+    }
+    getchar();
+    return 0;
+}
+
diff --git a/codes/c/chapter_computational_complexity/worst_best_time_complexity.c b/codes/c/chapter_computational_complexity/worst_best_time_complexity.c
new file mode 100644
index 00000000..88ed4dd2
--- /dev/null
+++ b/codes/c/chapter_computational_complexity/worst_best_time_complexity.c
@@ -0,0 +1,55 @@
+/*
+ * File: worst_best_time_complexity.c
+ * Created Time: 2023-01-03
+ * Author: sjinzh (sjinzh@gmail.com)
+ */
+
+#include "../include/include.h"
+
+/* 生成一个数组，元素为 { 1, 2, ..., n }，顺序被打乱 */
+int *randomNumbers(int n) {
+    // 分配堆区内存（创建一维可变长数组：数组中元素数量为n，元素类型为int）
+    int *nums = (int *)malloc(n * sizeof(int));
+    // 生成数组 nums = { 1, 2, 3, ..., n }
+    for (int i = 0; i < n; i++) {
+        nums[i] = i + 1;
+    }
+    // 随机打乱数组元素 
+	for (int i = n - 1; i > 0; i--) {
+		int j = rand() % (i + 1);
+		int temp = nums[i];
+		nums[i] = nums[j];
+		nums[j] = temp; 
+	}
+    return nums;
+}
+
+/* 查找数组 nums 中数字 1 所在索引 */
+int findOne(int *nums, int n) {
+    for (int i = 0; i < n; i++) {
+        if (nums[i] == 1) return i;
+    }
+    return -1;
+}
+
+/* Driver Code */
+int main(int argc, char *argv[]) {
+    // 初始化随机数种子
+    srand((unsigned int)time(NULL));
+    for (int i = 0; i < 10; i++) {
+        int n = 100;
+        int *nums = randomNumbers(n);
+        int index = findOne(nums, n);
+        printf("\n数组 [ 1, 2, ..., n ] 被打乱后 = ");
+        printArray(nums, n);
+        printf("数字 1 的索引为 %d\n", index);
+        // 释放堆区内存
+        if (nums != NULL) {
+            free(nums);
+            nums = NULL;
+        }
+    }
+    getchar();
+    return 0;
+}
+
diff --git a/codes/c/include/include.h b/codes/c/include/include.h
index 02858b67..c567aa2e 100644
--- a/codes/c/include/include.h
+++ b/codes/c/include/include.h
@@ -1,12 +1,15 @@
-/*
- * File: include.h
- * Created Time: 2022-12-20
- * Author: MolDuM (moldum@163.com)
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdbool.h>
-
-#include "PrintUtil.h"
+/*
+ * File: include.h
+ * Created Time: 2022-12-20
+ * Author: MolDuM (moldum@163.com)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+#include <time.h>
+
+#include "PrintUtil.h"
+
+
diff --git a/docs/chapter_computational_complexity/time_complexity.md b/docs/chapter_computational_complexity/time_complexity.md
index 539c9b5c..42bf2c25 100644
--- a/docs/chapter_computational_complexity/time_complexity.md
+++ b/docs/chapter_computational_complexity/time_complexity.md
@@ -91,7 +91,16 @@ $$
 === "C"
 
     ```c title=""
-
+    // 在某运行平台下
+    void algorithm(int n) {
+        int a = 2;  // 1 ns
+        a = a + 1;  // 1 ns
+        a = a * 2;  // 10 ns
+        // 循环 n 次
+        for (int i = 0; i < n; i++) {   // 1 ns ，每轮都要执行 i++
+            printf("%d", 0);            // 5 ns
+        }
+    }
     ```
 
 === "C#"
@@ -232,7 +241,22 @@ $$
 === "C"
 
     ```c title=""
-
+    // 算法 A 时间复杂度：常数阶
+    void algorithm_A(int n) {
+        printf("%d", 0);
+    }
+    // 算法 B 时间复杂度：线性阶
+    void algorithm_B(int n) {
+        for (int i = 0; i < n; i++) {
+            printf("%d", 0);
+        }
+    }
+    // 算法 C 时间复杂度：常数阶
+    void algorithm_C(int n) {
+        for (int i = 0; i < 1000000; i++) {
+            printf("%d", 0);
+        }
+    }
     ```
 
 === "C#"
@@ -373,7 +397,15 @@ $$
 === "C"
 
     ```c title=""
-
+    void algorithm(int n) {
+        int a = 1;  // +1
+        a = a + 1;  // +1
+        a = a * 2;  // +1
+        // 循环 n 次
+        for (int i = 0; i < n; i++) {   // +1（每轮都执行 i ++）
+            printf("%d", 0);            // +1
+        }
+    }  
     ```
 
 === "C#"
@@ -542,7 +574,20 @@ $$
 === "C"
 
     ```c title=""
-
+    void algorithm(int n) {
+        int a = 1;  // +0（技巧 1）
+        a = a + n;  // +0（技巧 1）
+        // +n（技巧 2）
+        for (int i = 0; i < 5 * n + 1; i++) {
+            printf("%d", 0);
+        }
+        // +n*n（技巧 3）
+        for (int i = 0; i < 2 * n; i++) {
+            for (int j = 0; j < n + 1; j++) {
+                printf("%d", 0);
+            }
+        }
+    }
     ```
 
 === "C#"
@@ -697,7 +742,16 @@ $$
 === "C"
 
     ```c title="time_complexity.c"
-
+    /* 常数阶 */
+    int constant(int n) {
+        int count = 0;
+        int size = 100000;
+        int i = 0;
+        for (int i = 0; i < size; i++) {
+            count ++;
+        }
+        return count;
+    }
     ```
 
 === "C#"
@@ -795,7 +849,14 @@ $$
 === "C"
 
     ```c title="time_complexity.c"
-
+    /* 线性阶 */
+    int linear(int n) {
+        int count = 0;
+        for (int i = 0; i < n; i++) {
+            count ++;
+        }
+        return count;
+    }
     ```
 
 === "C#"
@@ -899,7 +960,15 @@ $$
 === "C"
 
     ```c title="time_complexity.c"
-
+    /* 线性阶（遍历数组） */
+    int arrayTraversal(int *nums, int n) {
+        int count = 0;
+        // 循环次数与数组长度成正比
+        for (int i = 0; i < n; i++) {
+            count ++;
+        }
+        return count;
+    }
     ```
 
 === "C#"
@@ -1012,7 +1081,17 @@ $$
 === "C"
 
     ```c title="time_complexity.c"
-
+    /* 平方阶 */
+    int quadratic(int n) {
+        int count = 0;
+        // 循环次数与数组长度成平方关系
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < n; j++) {
+                count ++;
+            }
+        }
+        return count;
+    }
     ```
 
 === "C#"
@@ -1163,7 +1242,23 @@ $$
 === "C"
 
     ```c title="time_complexity.c"
-
+    /* 平方阶（冒泡排序） */
+    int bubbleSort(int *nums, int n) {
+        int count = 0;  // 计数器 
+        // 外循环：待排序元素数量为 n-1, n-2, ..., 1
+        for (int i = n - 1; i > 0; i--) {
+            // 内循环：冒泡操作
+            for (int j = 0; j < i; j++) {
+                // 交换 nums[j] 与 nums[j + 1]
+                int tmp = nums[j];
+                nums[j] = nums[j + 1];
+                nums[j + 1] = tmp;
+                count += 3;  // 元素交换包含 3 个单元操作
+            }
+            
+        }
+        return count;
+    }
     ```
 
 === "C#"
@@ -1309,7 +1404,20 @@ $$
 === "C"
 
     ```c title="time_complexity.c"
-
+    /* 指数阶（循环实现） */
+    int exponential(int n) {
+        int count = 0;
+        int bas = 1;
+        // cell 每轮一分为二，形成数列 1, 2, 4, 8, ..., 2^(n-1)
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < bas; j++) {
+                count++;
+            }
+            bas *= 2;
+        }
+        // count = 1 + 2 + 4 + 8 + .. + 2^(n-1) = 2^n - 1
+        return count;
+    }
     ```
 
 === "C#"
@@ -1414,7 +1522,11 @@ $$
 === "C"
 
     ```c title="time_complexity.c"
-
+    /* 指数阶（递归实现） */
+    int expRecur(int n) {
+        if (n == 1) return 1;
+        return expRecur(n - 1) + expRecur(n - 1) + 1;
+    }
     ```
 
 === "C#"
@@ -1517,7 +1629,15 @@ $$
 === "C"
 
     ```c title="time_complexity.c"
-
+    /* 对数阶（循环实现） */
+    int logarithmic(float n) {
+        int count = 0;
+        while (n > 1) {
+            n = n / 2;
+            count++;
+        }
+        return count;
+    }
     ```
 
 === "C#"
@@ -1613,7 +1733,11 @@ $$
 === "C"
 
     ```c title="time_complexity.c"
-
+    /* 对数阶（递归实现） */
+    int logRecur(float n) {
+        if (n <= 1) return 0;
+        return logRecur(n / 2) + 1;
+    }
     ```
 
 === "C#"
@@ -1720,7 +1844,16 @@ $$
 === "C"
 
     ```c title="time_complexity.c"
-
+    /* 线性对数阶 */
+    int linearLogRecur(float n) {
+        if (n <= 1) return 1;
+        int count = linearLogRecur(n / 2) +
+                    linearLogRecur(n / 2);
+        for (int i = 0; i < n; i++) {
+            count ++;
+        }
+        return count;
+    }
     ```
 
 === "C#"
@@ -1845,7 +1978,15 @@ $$
 === "C"
 
     ```c title="time_complexity.c"
-
+    /* 阶乘阶（递归实现） */
+    int factorialRecur(int n) {
+        if (n == 0) return 1;
+        int count = 0;
+        for (int i = 0; i < n; i++) {
+            count += factorialRecur(n - 1);
+        }
+        return count;
+    }
     ```
 
 === "C#"
@@ -2061,7 +2202,52 @@ $$
 === "C"
 
     ```c title="worst_best_time_complexity.c"
+    /* 生成一个数组，元素为 { 1, 2, ..., n }，顺序被打乱 */
+    int *randomNumbers(int n) {
+        // 分配堆区内存（创建一维可变长数组：数组中元素数量为n，元素类型为int）
+        int *nums = (int *)malloc(n * sizeof(int));
+        // 生成数组 nums = { 1, 2, 3, ..., n }
+        for (int i = 0; i < n; i++) {
+            nums[i] = i + 1;
+        }
+        // 随机打乱数组元素 
+        for (int i = n - 1; i > 0; i--) {
+            int j = rand() % (i + 1);
+            int temp = nums[i];
+            nums[i] = nums[j];
+            nums[j] = temp; 
+        }
+        return nums;
+    }
 
+    /* 查找数组 nums 中数字 1 所在索引 */
+    int findOne(int *nums, int n) {
+        for (int i = 0; i < n; i++) {
+            if (nums[i] == 1) return i;
+        }
+        return -1;
+    }
+
+    /* Driver Code */
+    int main(int argc, char *argv[]) {
+        // 初始化随机数种子
+        srand((unsigned int)time(NULL));
+        for (int i = 0; i < 10; i++) {
+            int n = 100;
+            int *nums = randomNumbers(n);
+            int index = findOne(nums, n);
+            printf("\n数组 [ 1, 2, ..., n ] 被打乱后 = ");
+            printArray(nums, n);
+            printf("数字 1 的索引为 %d\n", index);
+            // 释放堆区内存
+            if (nums != NULL) {
+                free(nums);
+                nums = NULL;
+            }
+        }
+        getchar();
+        return 0;
+    }
     ```
 
 === "C#"