简单的计算器

输入1+1

输出2

#include <iostream>#include <string >#include <vector>#include <algorithm>using namespace std;int main(){ostream_iterator<int> output(cout," ");  string s;  getline(cin,s);  int count=0;  for(int i=0;i<s.size();i++)  {  if(s[i]=='+'||s[i]=='-')  count++;  }  if(count!=1)  cout<<0;  else  {    const char *st=s.c_str();    char *str=(char *)malloc(sizeof(char)*s.size());    strcpy(str,st);    char *p=strtok(str,"+");    vector<int> input;vector<char> oper;    while(p)    {      input.push_back(atoi(p));  p=strtok(NULL,"+");    }copy(input.begin(),input.end(),output);if(s.find('+')!=string::npos)cout<<(input[0]+input[1]);else if(s.find('-')!=string::npos)cout<<(input[0]-input[1]);  }  system("pause");return 0;}