diff --git a/src/12/c12/SecondOrderDifference.cpp b/src/12/c12/SecondOrderDifference.cpp
new file mode 100644
index 0000000..5f0da6b
--- /dev/null
+++ b/src/12/c12/SecondOrderDifference.cpp
@@ -0,0 +1,5 @@
+
+
+int main(){
+    
+}
\ No newline at end of file
diff --git a/src/12/c12/func.py b/src/12/c12/func.py
new file mode 100644
index 0000000..0a9b86e
--- /dev/null
+++ b/src/12/c12/func.py
@@ -0,0 +1,38 @@
+import numpy as np
+import matplotlib.pyplot as plt
+
+# 给定的数列
+sequence = [33, -66, 99, -33, 0, 0, 66, -33, 33, 33, -33, 33, 0, 53, -27, 27, 46, -33, 
+            366, -933, 966, -333, 66, 0, 0, 33, 66, -66, 66, 33, -33, 66, 33, 0, 0, 66]
+
+# 计算相邻数值的差分
+diff = np.diff(sequence)
+
+# 输出差分
+print("原数列的差分：", diff)
+
+# 绘制原数列和差分图
+plt.figure(figsize=(10, 5))
+
+# 原数列的图像
+plt.subplot(1, 2, 1)
+plt.plot(sequence, label="原数列")
+plt.title("原数列")
+plt.xlabel("索引")
+plt.ylabel("值")
+
+# 差分图像
+plt.subplot(1, 2, 2)
+plt.plot(diff, label="差分", color='orange')
+plt.title("差分图")
+plt.xlabel("索引")
+plt.ylabel("差值")
+
+plt.tight_layout()
+plt.show()
+
+# 计算数列的其他统计量
+mean = np.mean(sequence)
+std = np.std(sequence)
+print(f"数列的均值: {mean}")
+print(f"数列的标准差: {std}")
diff --git a/src/12/c12/nums.txt b/src/12/c12/nums.txt
new file mode 100644
index 0000000..05b55ae
--- /dev/null
+++ b/src/12/c12/nums.txt
@@ -0,0 +1,39 @@
+2 99
+3 264
+4 528
+5 924
+6 1386
+7 2013
+8 2772
+9 3663
+10 4686
+11 5907
+12 7293 
+13 8877
+14 10692
+15 12705
+16 14949
+17 17424
+18 20183 
+19 23199 
+20 26499 
+21 30129 
+22 34056 
+23 38646
+24 42966 
+25 47982 
+26 53361 
+27 59169 
+28 65406
+29 72072
+30 79200
+31 86856 
+32 94974 
+33 103620 
+34 112827 
+35 122562 
+36 132891 
+37 143847 
+38 155430 
+39 167640 
+40 180543
\ No newline at end of file
diff --git a/src/12/c12/test.py b/src/12/c12/test.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/12/c13/c13_t1.cpp b/src/12/c13/c13_t1.cpp
new file mode 100644
index 0000000..e69de29
diff --git a/src/12/c13/c13_t1.png b/src/12/c13/c13_t1.png
new file mode 100644
index 0000000..6a40a8b
Binary files /dev/null and b/src/12/c13/c13_t1.png differ