source :: Accelerated C++ 2~4장까지 작성한 프로그램

AccCplusplus.cpp

#include <algorithm> 
#include <iomanip> 
#include <ios> 
#include <iostream> 
#include <string> 
#include <vector> 
#include <stdexcept> 

usingstd::cin; 
usingstd::cout; 
usingstd::endl; 

usingstd::setprecision; 
usingstd::streamsize; 
usingstd::domain_error; 

usingstd::sort; 
usingstd::vector; 
usingstd::string; 
usingstd::istream; 
usingstd::max; 

/* 학생데이터 구조체 */
struct Student_info 
{ 
string name; 
double midterm,final; 
    vector<double> homework; 
}; 

/* 중앙값 계산 함수 */
double median(vector<double> vec) 
{ 
typedef vector<double>::size_type vec_sz; 

    vec_sz size = vec.size(); 

/* 예외 처리 */
if(size==0) 
throw domain_error("median of anempty vector"); 

    sort(vec.begin(), vec.end()); 

    vec_sz mid = size/2; 

return (size % 2 == 0) ? (vec[mid]+vec[mid-1]) / 2 : vec[mid]; 
} 

/* 성적 계산 함수 */
double grade(double midterm,double final,double homework) 
{ 
return0.2 * midterm + 0.4 * final  + 0.4 * homework; 
} 

/* 데이터 예외처리 함수 */
double grade(double midterm,double final, const vector<double>& hw) 
{ 
if(hw.size() == 0) 
throw domain_error("student has done no homework"); 
return grade(midterm, final, median(hw)); 
} 

/* 학생 데이터 처리 함수 */
double grade(const Student_info& s) 
{ 
return grade(s.midterm,s.final,s.homework); 
} 

/* 과제성적 저장 함수 */
istream& read_hw(istream& in,vector<double>& hw) 
{ 
if(in) 
    { 
        hw.clear(); 
double x; 
cout<<"homework score :"; 
while(in >> x) 
            hw.push_back(x); 
        in.clear(); 
    } 
return in; 
} 

/* 시험 성적 입력 함수 */
istream& read(istream& is,Student_info& s) 
{ 
cout<<"name,mid,final(Exit is Ctrl+Z) : "; 
    is>>s.name>>s.midterm>>s.final; 

    read_hw(is,s.homework); 
return is; 
} 

/* 학생이름 대소 비교 함수 */
bool compare(const Student_info& x, const Student_info& y) 
{ 
return x.name < y.name; 
} 

int main() 
{ 
    vector<Student_info> students; 
    Student_info record; 
string::size_type maxlen = 0; 

while(read(cin,record)) 
    { 
// 가장 긴 이름의 길이를 얻어냄
        maxlen = max(maxlen,record.name.size()); 
        students.push_back(record); 
    } 

// 문자열 대소 비교를 위해 직접 작성한 compare함수를 세번째 인자로 전달 
    sort(students.begin(), students.end(), compare); 

for(vector<Student_info>::size_type i=0; i!=students.size(); ++i) 
    { 
// 오른쪽에 maxlen+1 개의 공백문자를 포함한 이름을 출력
cout<<students[i].name 
            <<string(maxlen+1 - students[i].name.size(),' '); 

try    { 
double final_grade = grade(students[i]); 
            streamsize prec = cout.precision(); 
cout<<setprecision(3)<<final_grade 
                <<setprecision(prec); 
        } catch(domain_error e)    { 
cout<< e.what(); 
        } 

cout<<endl; 
    } 

return0; 
}