查找string中单词的个数

#include <iostream>

#include <cctype>

#include <string>

#include <vector>

using namespace std;

int Sum(string s)

{
int num = 0;

for (decltype(s.size()) index = 0; index != s.size(); ++index)
{
if (isspace(s[index]))
{
num++;//最后一位也是空格，但 要是最后不是呢，未考虑
}
}

return num;

}

int main()

{

string a = "This is a Temp huhu and lala";
int num = 0;
string::size_type i = a.size();
if (isspace(a[i-1]))//最后一位是空格
num = Sum(a);
else
{
num = Sum(a) + 1;
}
cout << num << endl;
getchar();
return 0;

}