L1-025 正整数A+B

#include<iostream>
#include<cstdio>
#include<string.h>
#include<string>
#include<math.h>
#include<queue>
#define maxn 1000005
using namespace std;
typedef long long ll;
int n,sum;
int a[maxn];
char s[maxn];
int main()
{
    cin.getline(s,maxn);
    int len=strlen(s);
    int pos=0;
    for(int i=0;i<len;i++)
    {
        if(s[i]==‘ ‘)
        {
            pos=i;
            break;
        }
    }
    int sum1=0,sum2=0,f1=0,f2=0;
    for(int i=0;i<pos;i++)
    {
        if(isdigit(s[i]))
            sum1=(s[i]-‘0‘)+sum1*10;
        else
        {
            f1=1;
            break;
        }
    }
    for(int i=pos+1;i<len;i++)
    {
        if(isdigit(s[i]))
            sum2=(s[i]-‘0‘)+sum2*10;
        else
        {
            f2=1;
            break;
        }
    }
    if(sum1<1||sum1>1000)
        f1=1;
    if(sum2<1||sum2>1000)
        f2=1;
    if(f1==0&&f2==0)
        printf("%d + %d = %d\n",sum1,sum2,sum1+sum2);
    else if(f1==0&&f2==1)
        printf("%d + ? = ?\n",sum1);
    else if(f1==1&&f2==0)
        printf("? + %d = ?\n",sum2);
    else
        printf("? + ? = ?\n");
    return 0;
}