diff --git a/c5.md b/c5.md
new file mode 100644
index 0000000..e292cc9
--- /dev/null
+++ b/c5.md
@@ -0,0 +1,4 @@
+int Ascending(float a, float b)
+{
+    return a < b;      // 这样比较决定了按升序排序，如果a<b，则交换 
+}
\ No newline at end of file
diff --git a/c6.md b/c6.md
new file mode 100644
index 0000000..87b96ea
--- /dev/null
+++ b/c6.md
@@ -0,0 +1,4 @@
+int Descending(float a, float b)
+{
+    return a > b;
+}
\ No newline at end of file
diff --git a/c7.md b/c7.md
new file mode 100644
index 0000000..8dbf3db
--- /dev/null
+++ b/c7.md
@@ -0,0 +1,7 @@
+void  SwapFloat(float *x, float *y)
+{
+float temp;
+temp = *x;
+*x = *y;
+*y = temp;
+}
\ No newline at end of file
diff --git a/c8.md b/c8.md
new file mode 100644
index 0000000..68f1b39
--- /dev/null
+++ b/c8.md
@@ -0,0 +1,7 @@
+void  SwapLong(long *x, long *y)
+{
+long   temp;
+temp = *x; 
+*x = *y;  
+*y = temp;
+}
\ No newline at end of file