newcerr.cpp

C++的常用算法

//这个程序在本书所带软盘中，文件名为NEWCERR.CPP
//这个程序利用cerr来处理动态地址字节分配时以及输入时的错误。

#include <iostream.h>
#include <conio.h>
#include <ctype.h>

void main(void)
{
	int size;
	float sum,average;
	char choice;

	do {
		cout << "please enter number of student in the class: ";
		cin >> size;
		cout << endl;

		sum = 0;

		float *score = new float[size];		//动态分配地址字节
		if (score == NULL)
			cerr << endl << "Error allocating memory! Try use smaller number..." << endl;
		else if (cin.fail())
			cerr << endl << "Error reading input! Try use right input..." << endl;
		else {
			for (int i = 0; i < size; i++) {
				cout << endl << "Please enter student " << (i+1) << "'s score: ";
				cin >> score[i];
				sum += score[i];
			}
			average = sum/size;

			delete score;						//把地址空间释放回系统

			cout << endl << "The average score of the class is: " << average << endl;
		}
		cout << "Do you want to compute another class's average?(y/n): ";
		choice = getche();
		cout << endl;
	} while(toupper(choice) == 'Y');
}