// Geoff Hagopian PPP4 exercise 4

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int guessing();

int main() {
	cout << "Think of a number between 1 and 100.\n";
	cout << "Your number is " << guessing();
}

int guessing() {
	int leftVal = 1, rightVal = 100;
	char ans;
	while (rightVal - leftVal > 1) {
		cout << "Is your number less than "
			<< leftVal + (rightVal - leftVal) / 2
			<< " ? (y/n)";
		cin >> ans;
		if (ans == 'y') {
			rightVal = leftVal + (rightVal - leftVal) / 2;
		}
		else if (ans == 'n') {
			leftVal = leftVal + (rightVal - leftVal) / 2;
		}
		else cout << "I didn't understant that.\n";
	}
	return leftVal;
}