C++ strin 4000 g转换long long

我们用stringstream进行转换

#include <iostream>
#include <sstream>
using namespace std;

int main()
{
string strLLNum = "1234567890123";
stringstream strIn;
strIn<<strLLnum;
long long llNum;
strIn>>llNum;
cout<<llNum;
return 0;
}