lab11_1.cpp

#include<iostream>
#include<string>
using namespace std;

int main(){
	int count[5] = {}; //Declare array count for counting A,B,C,D,F and initialize all element = 0
	cout << "Please input grade of each student (A-F) or input 0 to exit.\n";
	int i=1;
	string A, B, C, D, F,grade;
	do{
		cout << "Student [" <<i<<"]: ";
		getline(cin,grade); //The loop must be terminated when grade = '0'
		if(grade=="A")
		{
			++count[0];
		}else if(grade=="B")
		{
			++count[1];
		}else if(grade=="C")
		{
			++count[2];
		}else if(grade=="D")
		{
			++count[3];
		}else if(grade=="F")
		{
			++count[4];
		}else if(grade=="0")
		{
		    break;
		}else{ 
			cout<<"Wrong input. Please input again.\n";
			i--;
		}
		i++; 
	}while(grade!="0");
	cout << "In total "<<i-1<<" students.\n";
	cout << "A = " << count[0] <<", ";
	cout << "B = " << count[1] <<", ";	
	cout << "C = " << count[2] <<", ";
	cout << "D = " << count[3] <<", ";
	cout << "F = " << count[4] ;
	return 0;
}