需要帮助按字母顺序排序数组

Question

我必须按字母顺序对姓氏进行排序，我一直在寻找如何做到这一点的时间，但我的垃圾书除了整数之外没有提供任何例子，所以任何帮助都会很棒。这是我的代码：

#include <cstdlib>
#include <iostream>
#include <iomanip>


using namespace std;

int getAverage(int,int,int);
string letterGrade(int);
void getInfo();

 int main(int argc, char *argv[])
{
getInfo();
system("PAUSE");
return EXIT_SUCCESS;
}

void getInfo()
{
const int info = 5;
string last[info];
string first[info];
int ID[info];
int score1[info];
int score2[info];
int score3[info];

for (int count = 0; count < info; count++)
    {
         cout << "last name\n";
         cin >> last[count];
         cout << "first name\n";
         cin >> first[count];
         cout << "enter ID\n";
         cin >> ID[count];
         cout << "enter test 1\n";
         cin >> score1[count];
         cout << "enter test 2\n";
         cin >> score2[count];
         cout << "enter test 3\n";
         cin >> score3[count];

    }

    cout << endl;

    for (int count = 0; count < info; count++)
    {

     cout << last[count] 
     << setw(10) << first[count] 
     << setw(10) << ID[count] 
     << setw(10) <<score1[count]
     << setw(10) << score2[count] 
     << setw(10) << score3[count] 
     << setw(10) << getAverage(score1[count],score2[count],score3[count])
     << setw(10) <<  letterGrade(getAverage(score1[count],score2[count],score3[count]));


        cout << endl;
    }

}
string letterGrade(int average)
{
   string lGrade;

    if (average > 89)
        lGrade = "A";
    else if (average > 79 && average < 90)
        lGrade = "B";
    else if (average > 69 && average < 80)
        lGrade = "C";
    else if (average > 59 && average < 70)
        lGrade = "D";
    else if (average >= 0 && average < 60)
        lGrade = "F";
    return lGrade;
}
int getAverage(int score1,int score2,int score3)
{
 int average;
 average = ((score1 + score2 + score3)/ 3);
 return average;
}

Answer 1

我建议使用struct i / o一堆数组和std :: sort（假设你可以这样做）。

#include <cstdlib>
#include <iostream>
#include <iomanip>
#include <algorithm>
#include <vector>


using namespace std;

int getAverage(int,int,int);
string letterGrade(int);
void getInfo();

struct gradeInfo {
    string last;
    string first;
    int ID;
    int score1;
    int score2;
    int score3;
};

bool mySort (gradeInfo g1,gradeInfo g2) { 
    return (g1.last <g2.last); 
} //lexicographical string comparison

 int main(int argc, char *argv[])
{
getInfo();
system("PAUSE");
return EXIT_SUCCESS;
}

void getInfo()
{
const int info = 5;
vector<gradeInfo> grades;

for (int count = 0; count < info; count++)
    {
         gradeInfo gradesEntry;
         cout << "last name\n";
         cin >> gradesEntry.last;
         cout << "first name\n";
         cin >> gradesEntry.first;
         cout << "enter ID\n";
         cin >> gradesEntry.ID;
         cout << "enter test 1\n";
         cin >> gradesEntry.score1;
         cout << "enter test 2\n";
         cin >> gradesEntry.score2;
         cout << "enter test 3\n";
         cin >> gradesEntry.score3;
         grades.push_back(gradesEntry);
    }

    cout << endl;

    sort(grades.begin(), grades.end(), mySort);

    for (int count = 0; count < info; count++)
    {
     int average = getAverage(grades[count].score1,grades[count].score2,grades[count].score3);
     cout << grades[count].last 
     << setw(10) << grades[count].first 
     << setw(10) << grades[count].ID 
     << setw(10) << grades[count].score1
     << setw(10) << grades[count].score2 
     << setw(10) << grades[count].score3
     << setw(10) << average
     << setw(10) <<  letterGrade(average);


        cout << endl;
    }

}
string letterGrade(int average)
{
   string lGrade;

    if (average > 89)
        lGrade = "A";
    else if (average > 79 && average < 90)
        lGrade = "B";
    else if (average > 69 && average < 80)
        lGrade = "C";
    else if (average > 59 && average < 70)
        lGrade = "D";
    else if (average >= 0 && average < 60)
        lGrade = "F";
    return lGrade;
}
int getAverage(int score1,int score2,int score3)
{
 int average;
 average = ((score1 + score2 + score3)/ 3);
 return average;
}