```
#include<bits/stdc++.h>
using namespace std;
int i,a,b,c,p;//a,b,c是每个位置的值；p是循环所在的部分
string s;
char x;//x是加减的符号
int main(){
getline(cin,s);
for(i=0;i<s.size();i++){
if(s[i]==' ') continue;
else if(s[i]>='0'&&s[i]<='9'){
if(p==0) a=a*10+(s[i]-'0');
else if(p==1) b=b*10+(s[i]-'0');
else if(p==2) c=c*10+(s[i]-'0');
}
else if(s[i]=='+'||s[i]=='-'){p=1; x=s[i];}
else if(s[i]=='=') p=2;
}
if(a==0){
if(x=='+')//?+2=3
cout<<c-b;
else if(x=='-')//?-2=3
cout<<b+c;
}
else if(b==0){
if(x=='+')//2+?=3
cout<<c-a;
else if(x=='-')//3-?=2
cout<<a-c;
}
else if(c==0){
if(x=='+')//2+3=?
cout<<a+b;
else if(x=='-')//3-2=?
cout<<a-b;
}
return 0;
}
```
by YangjinRun @ 2022-05-27 19:13:30
纯属简单易懂了hhh
by YangjinRun @ 2022-05-27 19:14:15
YYDS NB!!!
爱你
by billifs @ 2022-05-27 19:15:17