文件读写和成绩排序

#include <iostream>
#include <vector>
#include <cmath>
#include<fstream>
#include <string>
#include<algorithm>

using namespace std;

typedef struct stu {
	string name;
	int age;
	double score;
	stu(){}
	stu(string sname,int sage,double sscore):name(sname),age(sage),score(sscore){}
}Student;

bool cmpBigger(const Student& stu1, const Student& stu2) {
	return stu1.score > stu2.score;
}




class Solution
{
private:
	vector<Student> m_StudentTable;
public:
	Solution() {}
	~Solution() {}

	void readFromConsole(){
		string stuName = "";
		int age = 0;
		double score = 0.0;

		for (int i = 0; i < 4; i++) {
			cin >> stuName >> age >> score;
			m_StudentTable.push_back(stu(stuName, age, score));
		}
	}

	void writeToFile(const string& fileAddress) {
		ofstream outputToFile(fileAddress, ios::out);
		for (Student stu : m_StudentTable) {
			outputToFile << stu.name << " " << stu.age << " " << stu.score << endl;
		}
		outputToFile.close();
	}

	void readFromFile(const string& fileAddress) {
		m_StudentTable.clear();
		Student stu;

		ifstream inputFromFile(fileAddress, ios::in);
		for (int i = 0; i < 4; i++) {
			inputFromFile >> stu.name >> stu.age >> stu.score;
			m_StudentTable.push_back(stu);
		}
		
		inputFromFile.close();
	}

	void sortByScoresUp() {
		sort(m_StudentTable.begin(), m_StudentTable.end(),cmpBigger);
	}

	void showHighestScoreStudent() {
		Student HighestScoreStudent = m_StudentTable.at(0);
		cout << "成绩最高的学生信息： "<<HighestScoreStudent.name << " " << HighestScoreStudent.age
			<< " " << HighestScoreStudent.score << endl;
	}

};


int main()
{
	Solution test;
	string file("d:\\Student.txt");
	test.readFromConsole();
	test.writeToFile(file);
	test.readFromFile(file);
	test.sortByScoresUp();
	test.showHighestScoreStudent();
	system("pause");
	return 0;
}

文件读出并查找

#include <vector>
#include <set>
#include<iostream>
#include <string>
#include <fstream>

using namespace std;
//学号、姓名、性别和年龄

typedef struct student {
	string stuNumber;
	string stuName;
	int stuSex;
	int stuAge;
}Student;

class Solution {
private:
	vector<Student> StuTable;
public:
	Solution(){}
	~Solution() {}
	
	void readInfoFromFile(string fileAddr) {
		ifstream readFromFile(fileAddr, ios::in);

		while (!readFromFile.eof()) {
			Student temp;
			readFromFile >> temp.stuNumber 
				>> temp.stuName 
				>> temp.stuSex 
				>> temp.stuAge;
			StuTable.push_back(temp);
		}
	}
	void findStudent(string stuNum) {
		bool has = false;
		for (int i = 0; i < StuTable.size(); i++) {
			if (StuTable[i].stuNumber == stuNum) {
				showInfoOfStudent(i);
				has = true;
			}
		}

		if (!has){
			cout << "The student is not in table!" << endl;
		}
	}
	
	void showInfoOfStudent(int order) {
		cout<<"The student info : \n"
			<< StuTable[order].stuNumber <<" "
			<< StuTable[order].stuName << " " 
			<< StuTable[order].stuSex << " "
			<< StuTable[order].stuAge <<endl;
	}
	
};



int main()
{
	Solution test;
	test.readInfoFromFile("d:\\Student.txt");
	test.findStudent("07");
	
	system("pause");
	return 0;
}