feat: insertion sort in cpp (doocs#555)

Author: daliang111

basic/sorting/InsertionSort/InsertionSort.cpp

@@ -0,0 +1,42 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void printvec(const vector<int> &vec, const string &strbegin = "", const string &strend = "")
+{
+    cout << strbegin << endl;
+    for (auto val : vec)
+    {
+        cout << val << "\t";
+    }
+
+    cout << endl;
+    cout << strend << endl;
+}
+
+void insertsort(vector<int> &vec)
+{
+    for (int i = 1; i < vec.size(); i++)
+    {
+        int j = i - 1;
+        int num = vec[i];
+        for (; j >= 0 && vec[j] > num; j--)
+        {
+            vec[j + 1] = vec[j];
+        }
+
+        vec[j + 1] = num;
+    }
+
+    return;
+}
+
+int main()
+{
+    vector<int> vec = {9, 8, 7, 6, 5, 4, 3, 2, 1, 0};
+    printvec(vec);
+    insertsort(vec);
+    printvec(vec, "after insert sort");
+    return (0);
+}

basic/sorting/InsertionSort/README.md

@@ -85,6 +85,53 @@ func main() {
 }
 ```
 
+### **C++**
+
+```cpp
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void printvec(const vector<int> &vec, const string &strbegin = "", const string &strend = "")
+{
+    cout << strbegin << endl;
+    for (auto val : vec)
+    {
+        cout << val << "\t";
+    }
+
+    cout << endl;
+    cout << strend << endl;
+}
+
+void insertsort(vector<int> &vec)
+{
+    for (int i = 1; i < vec.size(); i++)
+    {
+        int j = i - 1;
+        int num = vec[i];
+        for (; j >= 0 && vec[j] > num; j--)
+        {
+            vec[j + 1] = vec[j];
+        }
+
+        vec[j + 1] = num;
+    }
+
+    return;
+}
+
+int main()
+{
+    vector<int> vec = {9, 8, 7, 6, 5, 4, 3, 2, 1, 0};
+    printvec(vec);
+    insertsort(vec);
+    printvec(vec, "after insert sort");
+    return (0);
+}
+```
+
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 ## 算法分析