眼瞎了A和B都在区间[1,1000]

C++ 代码

#include<iostream>
using namespace std;
int n1,n2;
bool f1,f2,f3,f4;
string a,b;
int main()
{
    f1=f2=f3=f4=true;
    cin>>a;
    getchar();
    getline(cin,b);
    for(int i=0;i<a.size();i++)
    {
        if(a[i]>='0'&&a[i]<='9')
        {
            n1=n1*10+(a[i]-'0');
        }
        else{
            f1=false;
            break;
        }
    }
    for(int i=0;i<b.size();i++)
    {
        if(b[i]>='0'&&b[i]<='9')
        {
            n2=n2*10+(b[i]-'0');
        }
        else{
            f2=false;
            break;
        }
    }
    if(n1>1000||n1<1)f3=false;
    if(n2>1000||n2<1)f4=false;
    if(f1&&f3)cout<<n1;
    else cout<<"?";
    cout<<" + ";
    if(f2&&f4)cout<<n2;
    else cout<<"?";
    cout<<" = ";
    if(f1&&f2&&f3&&f4)
        cout<<n1+n2;
    else cout<<"?";
    return 0;
}