四则运算

#include <bits/stdc++.h>
using namespace std;
int js(string a,string b);//计算 
//int jianfa(string a);
//int chengfa(string a);
//int chufa(string a);
string no1(string x);//清除空格 
int main(){
	string a;
	getline(cin,a);
	a=no1(a);
	if(a.find("+")>0 && a.find("+")<a.size()){
		cout<<js(a,"+");
	}else if(a.find("-")>0 && a.find("-")<a.size()){
		cout<<js(a,"-");
	}else if(a.find("*")>0 && a.find("*")<a.size()){
		cout<<js(a,"*");
	}else if(a.find("/")>0 && a.find("/")<a.size()){
		cout<<js(a,"/");
	}
	return 0;
}
string no1(string a){
	while(a.find(" ")>=0 && a.find(" ")<a.size()){
		a.replace(a.find(" "),1,"");
	}
	return a;
}
int js(string a,string b){
	int x = stoi(a.substr(0,a.find(b)));
    int y = stoi(a.substr(a.find(b)+1));
	if(b=="+"){
		return x+y;
	}if(b=="-"){
		return x-y;
	}if(b=="*"){
		return x*y;
	}if(b=="/"){
		return x/y;
	}
}