C++ 解法, 执行用时: 2ms, 内存消耗: 392KB, 提交时间: 2021-11-06

#include <iostream>
#include<string>
#include<vector>
using namespace std;

std::vector<string> str_fenge(const string &str,const string&patt)
{
    std::vector<string>vec;
    if (patt.empty() || str.empty())
        return vec;
    size_t start = 0;
    size_t index = str.find_first_of(patt, start);
    while (index != str.npos)
    {
        //if(start!=index)
            vec.push_back(str.substr(start, index - start));
        start = index + 1;
        index = str.find_first_of(patt, start);
    }
    if (!str.substr(start).empty())
    {
        vec.push_back(str.substr(start));
    }
    return vec;
}
int main() {

    char str[100] = { 0 };
    cin.getline(str, sizeof(str));

    // write your code here......
    string strs(str);
    string patt(" ");
   auto vec = str_fenge(str,patt);
   string ss=vec.at(0);
   int num1=atoi(vec.at(1).c_str());
   int num2=atoi(vec.at(2).c_str());
    
    if(ss.compare("add")==0)
    {
        cout<<num1+num2<<endl;
    }
    else if(ss.compare("sub")==0)
    {
         cout<<num1-num2<<endl;
    }
    else if(ss.compare("mul")==0)
    {
         cout<<num1*num2<<endl;
    }
    else if(ss.compare("div")==0)
    {
        if(num2==0)
        {
             cout<<"Error"<<endl;
            return -1;
        }  
         cout<<num1/num2<<endl;
    }
    else
    {
        
    }
    
    return 0;
}

C++ 解法, 执行用时: 2ms, 内存消耗: 392KB, 提交时间: 2021-10-24

#include <iostream>
#include <cstring>
using namespace std;
 
int main() {
 
    char str[100] = { 0 };
    cin.getline(str, sizeof(str));
 
    char* msg[30] = { str, nullptr };
 
    int i = 0;
 
    while ((msg[i] = strtok(msg[i], " ")) && ++i);
 
    char* op = msg[0];
    int num1 = atoi(msg[1]);
    int num2 = atoi(msg[2]);
     
    if (strcasecmp(op, "add") == 0) {
        cout << num1 + num2 << endl;
    }
    else if (strcasecmp(op, "sub") == 0) {
        cout << num1 - num2 << endl;
    }
    else if (strcasecmp(op, "mul") == 0) {
        cout << num1 * num2 << endl;
    }
    else if (strcasecmp(op, "div") == 0) {
        if (num2 == 0) {
            cout << "Error" << endl;
        }
        else {
            cout << (double)num1 / num2 << endl;
        }
    }
 
    return 0;
}

C++ 解法, 执行用时: 2ms, 内存消耗: 416KB, 提交时间: 2022-02-09

#include <iostream>
#include <cstring>
using namespace std;

int main() {

    char str[100] = { 0 };
    cin.getline(str, sizeof(str));
       
    char * msg[30] = {str,nullptr};
   
     int i = 0;
     while ((msg[i] = strtok(msg[i], " ")) && ++i);
      
     char *op = msg[0];
     int num1 = atoi(msg[1]);
    int num2 = atoi(msg[2]);
    
    if(strcasecmp(op,"add")==0){
      cout<<num1+num2<<endl;
    }
    
    else if(strcasecmp(op,"sub")==0){
       cout<<num1-num2<<endl;
     }
      else if(strcasecmp(op,"mul")==0){
       cout<<num1*num2<<endl;
     }else if(strcasecmp(op,"div")==0){
          if(num2==0){
              cout<<"Error";
          }else{
              cout<<num1/num2;
          }
      }
    // write your code here......
    

    return 0;
}

C++ 解法, 执行用时: 2ms, 内存消耗: 532KB, 提交时间: 2022-01-25

#include <iostream>
#include<string>
#include<cstring>
using namespace std;

int main() {

    char str[100] = { 0 };
    cin.getline(str, sizeof(str));
    // write your code here......
    size_t len = strlen(str);
	std::string way;
	std::string num1;
	std::string num2;
	int space = 0;
	for (int i = 0; i < len; i++)
	{
		if (str[i] == ' ')
			space++;
		else if (space == 0)
			way += (str[i]);
		else if (space == 1)
			num1 += str[i];
		else if (space == 2)
			num2 += str[i];
	}
	int nub1 = std::atoi(&num1[0]);
	int nub2 = std::atoi(&num2[0]);
	if (strcasecmp("add", way.c_str()) == 0)
		std::cout << nub1 + nub2 << std::endl;
	else if (strcasecmp("sub", way.c_str()) == 0)
		std::cout << nub1 - nub2 << std::endl;
	else if (strcasecmp("mul", way.c_str()) == 0)
		std::cout << nub1 * nub2 << std::endl;
	else if (strcasecmp("div", way.c_str()) == 0 && nub2 != 0)
		std::cout << nub1 / nub2 << std::endl;
	else if (nub2 == 0)
		std::cout << "Error" << std::endl;
    return 0;
}

C++ 解法, 执行用时: 3ms, 内存消耗: 304KB, 提交时间: 2021-10-16

#include <iostream>
#include <string.h>
#include <string>
#include<cstdlib>
using namespace std;

int main() {

	char str[100] = { 0 };
	cin.getline(str, sizeof(str));
    string op = "";
    string num1 = "";
    string num2 = "";
    int space = 0;
    for(int i = 0; str[i] != '\0'; i++){
        if(str[i] == ' '){
            space++;
            continue;
        }
        else if(space == 0) //第一空格之前都是操作符
            op += str[i]; 
        else if(space == 1) //第一二个空格之间，为第一个数字
            num1 += str[i];
        else if(space == 2)
            num2 += str[i]; //第二个空格之后，为第二个数字
    }
    int x = stoi(num1);
    int y = stoi(num2);
    if(strcasecmp(op.c_str(), "add") == 0)
        cout << x + y << endl;
    else if(strcasecmp(op.c_str(), "sub") == 0)
        cout << x - y << endl;
    else if(strcasecmp(op.c_str(), "mul") == 0)
        cout << x * y << endl;
    else if(strcasecmp(op.c_str(), "div") == 0){
        if(y == 0)
            cout << "Error" << endl;
        else
            cout << (double) x / y << endl;
    }
	return 0;
}