+=不能分开

a=a+b要写成a += b;不能a + = b;

#include<bits/stdc++.h>
using namespace std;
int main()
{
int a, b, x, y;
cin >> a >> b;
x = a += b;
//y = a + = b; 不能这样写会报错
cout << x <<endl << y;
return 0;
}