Add basic calculator functionality in test1.cpp

test1.cpp

@@ -0,0 +1,49 @@
+#include <string>
+#include "big_data_int.h"
+
+string getString(){
+    auto* str = new string();
+    str->reserve(100);
+    std::cout << "请输入内容：";
+    std::cin.getline(str->c_str(), 100);  // 直接读取到缓冲区
+
+    std::cout << "输入内容：" << str->c_str() << std::endl;
+
+    return str;
+}
+
+int main() 
+{
+    cout<<"please input two numbers:"<<endl;
+    string s_a, s_b;
+
+    s_a = getString();
+    s_b = getString();
+
+    cout<<"Please input the operator(+,-,*,/,%):"<<endl;
+    string op;
+    cin>>op;
+    big_data_int a(s_a), b(s_b), c;
+    switch (op.c_str()[0]) {
+        case '+':
+            c = a + b;
+            break;
+        case '-':
+            c = a - b;
+            break;
+        case '*':
+            c = a * b;
+            break;
+        case '/':
+            c = a / b;
+            break;
+        case '%':
+            c = a % b;
+            break;
+        default:
+            cout<<"Wrong operator input"<<endl;  
+            return -1;
+    }
+    cout <<"Result is:"<<endl<<c.data()<<endl;
+    return 0;
+}