算法入门经典P104-1（sstream）

#include<iostream>
#include<string>
#include<sstream>
using namespace std;
int main(){
    string line;
    while(getline(cin,line)){
        long long sum = 0,x;
        stringstream ss(line);
        while(ss>>x)sum += x;
        cout<<sum<<endl;
    }
    return 0;
}