PAT乙级1054 求平均值 （20 分）

题目链接

坑点（测试点2） 没看见！！！

只有一个有效数字

实现

#include 
#include 
#include 
#include 
using namespace std;


int main()
{
	int N,i;
	vector<double> nums;
	string str;
	cin >> N;
	for (i = 0; i < N; i++)
	{
		cin >> str;
		if (isalpha(str[0]) || str.find_first_of('.') != str.find_last_of('.') || (atof(str.c_str()) < -1000 || (str.find_first_of('.') != string::npos && str.size()-1 - (str.find_first_of('.'))>2)||atof(str.c_str()) > 1000))
			printf("ERROR: %s is not a legal number\n", str.c_str());
		else
			nums.push_back(atof(str.c_str()));		
	}
	if (nums.size() == 0)
		printf("The average of 0 numbers is Undefined\n");
	else
	{
		if (nums.size() == 1)
			printf("The average of 1 number is %.2f", nums[0]);
		else
		{
			double all = 0;
			for (i = 0; i < nums.size(); i++)
				all += nums[i];
			printf("The average of %d numbers is %.2f\n", nums.size(), all / nums.size());
		}
	}
	return 0;
}