How would i reject invalid inputs in my code? - c++

Question

I have no idea how i would reject invalid inputs for the exams and assignments (valid numbers are 0.00 - 100.00). but i also need to give the user one more chance to enter a valid input. so if they put in two invalid inputs in a row for the same variable it tells the user that they need to restart the program and prevent it from running. Im new to programming so im not very good at this.
#include <iostream>
#include <string>
#include <iomanip>
using namespace std;
int main ()
{
float exam_1;
float exam_2;
float exam_3;
float assignment_1;
float assignment_2;
float weighted_exam = .1667;
float weighted_assignment = .25;
float min_score = 0.00;
float max_score = 100.00;
string name;
cout << "Please enter student name <First Last>: "; // this will ask for the students first and last name
getline(cin, name);
cout << "\n";
cout << "\t Be sure to include the decimal point for scores.\n";
cout <<"\t !!! All scores should range from 0.00 to 100.00!!! \n";
cout << "\t For example: 80.50 \n";
cout << "\n";
cout << "Please enter your exam 1 score: ";
cin >> exam_1;
cout << "Please enter your exam 2 score: ";
cin >> exam_2;
cout << "Please enter your exam 3 score: ";
cin >> exam_3;
cout << "Please enter your assignment 1 score: ";
cin >> assignment_1;
cout << "Please enter your assignment 2 score: ";
cin >> assignment_2;
cout << endl;
cout << "-" << "OUTPUT" << "-\n";
return 0;
}

Answer 1

You can do like this:
do{
cout <<"\t !!! All scores should range from 0.00 to 100.00!!! \n";
cin >> exam_1;
while(exam_1 < 0.0 || exam_1>100.0);
Repeat this to all inputs

Answer 2

cout << "Please enter your exam 1 score: ";
cin >> exam_1;
cout << "Please enter your exam 2 score: ";
cin >> exam_2;
cout << "Please enter your exam 3 score: ";
cin >> exam_3;
To
auto ReadExamScore = [](auto& ex, char c)
{
cout << "Please enter your exam " << c << " score: ";
for (int i = 0; i < 2; i ++)
{
if (cin >> ex)
{
if (ex>= 0.0 && ex <= 100.00)
return true;
}
cout << "Please enter a valid exam score" << endl;
}
cout << "Press any key to exit..." << endl;
getchar();
exit(0);
};
ReadExamScore(exam_1,'1');
ReadExamScore(exam_2,'2');
ReadExamScore(exam_3,'3');