fix: do calcul in right order

ex00/src/BitcoinExchange.cpp

@@ -21,7 +21,6 @@ static bool is_leap(int year)
   
 static bool date_is_valid(int d, int m, int y)
 {
-    return false;
     if (m < 1 || m > 12)
 		return false;
     if (d < 1 || d > 31)

ex01/src/RPN.cpp

@@ -1,4 +0,0 @@
-#include <stack>
-#include <iostream>
-
-

ex01/src/main.cpp

@@ -16,10 +16,10 @@ int calculate(std::stack<int>& nums, std::stack<char>& operators)
 		return 0;
 
 	int ret;
-	int a = nums.top();
-	nums.pop();
 	int b = nums.top();
 	nums.pop();
+	int a = nums.top();
+	nums.pop();
 	
 	switch (operators.top()) {
 		case '+':
@@ -60,18 +60,20 @@ int main(int ac, char** av)
 		if (std::isdigit(av[1][i]))
 			nums.push(av[1][i] - '0');
 		else if (std::strchr("/+-*", av[1][i]) != NULL)
-			operators.push(av[1][i]);
-		else
 		{
-			std::cout << "error: '" << av[1][i] << "' unknown char" << std::endl;
+			operators.push(av[1][i]);
-			return 1;
-		}
 			if (calculate(nums, operators))
 			{
 				std::cout << "error: division by 0" << std::endl;
 				return 1;
 			}
 		}
+		else
+		{
+			std::cout << "error: '" << av[1][i] << "' unknown char" << std::endl;
+			return 1;
+		}
+	}
 	if (nums.size() != 1)
 	{
 		std::cout << "error: too many numbers" << std::endl;
@@ -79,7 +81,7 @@ int main(int ac, char** av)
 	}
 	if (operators.size() != 0)
 	{
-		std::cout << "error: too manu operators" << std::endl;
+		std::cout << "error: too many operators" << std::endl;
 		return 1;
 	}
 	std::cout << nums.top();