Chapter03

Author: 007kevin

Chapter03/ComputeStudentGrades.cpp

@@ -52,6 +52,7 @@ int main(){
                          conditions, they are automatically converted to bool. */
         ++count;
         sum += x;
+
     }
 
     /* write the result.

Chapter03/ComputeStudentGrades_v2.cpp

@@ -0,0 +1,53 @@
+#include <algorithm>
+#include <iomanip>
+#include <ios>
+#include <iostream>
+#include <string>
+#include <vector>
+
+using std::cin;             using std::sort;
+using std::cout;            using std::streamsize;
+using std::endl;            using std::string;
+using std::setprecision;    using std::vector;
+
+int main(){
+    cout << "Please enter your first name: ";
+    string name;
+    cin >> name;
+    cout << "Hello, " << name << "!" << endl;
+
+    cout << "Please enter your midterm and final grades: ";
+    double midterm, final;
+    cin >> midterm >> final;
+
+    cout << "Enter all your homework grades, "
+            "followed by end-of-file: ";
+
+    vector<double> homework;
+    double x;
+    //invariant: homework contains all the homework grades read so far
+    while (cin >> x)
+        homework.push_back(x);
+
+    typedef vector<double>::size_type vec_sz;
+    vec_sz size = homework.size();
+    if (size == 0){
+        cout << endl << "You must enter your grades. "
+                        "Please try again." << endl;
+
+        return 1;
+    }
+
+    sort(homework.begin(), homework.end());
+
+    vec_sz mid = size/2;
+    double median;
+    median = size % 2 == 0 ? (homework[mid] + homework[mid - 1]) / 2 : homework[mid];
+
+    streamsize prec = cout.precision();
+    cout << "Your final grade is " << setprecision(3)
+         << 0.2 * midterm + 0.4 * final + 0.4 * median
+         << setprecision(prec) << endl;
+
+    return 0;
+}