下载了数据输出和数据一样但全WA了

大佬求助！！

#include <bits/stdc++.h>
using namespace std;

int change(string s){
    int d;
    stringstream sin;
    sin<<s;
    sin>>d;
    return d;
}
string find(string s){
    string t="";
    for(int i=0;i<s.size();i++){
        if(isdigit(s[i])){
            t+=s[i];
        }else if(t!=""){
            return t;
        }
    }
    return "";
}
int findl(string s){
    for(int i=0;i<=s.size();i++){
        if(isdigit(s[i]))
            return i;
    }
    return -1;
}
int findr(string s){
    for(int i=findl(s);i<=s.size();i++){
        if(!isdigit(s[i+1]))
            return i;
    }
    return -1;
}
int main() {
    string s;
    int n;
    cin>>n;
    char ch;
    getchar();
    for(int i=1;i<=n;i++){
        getline(cin,s);
        char t[1000];
        if(s[0]>='a'&&s[0]<='c')ch=s[0];
        int l,r;
        l=change(find(s));
        s.erase(0,findr(s)+2);
        r=change(s);
        switch(ch){
            case 'a':
                sprintf(t,"%d+%d=%d",l,r,l+r);
                break;
            case 'b':
                sprintf(t,"%d-%d=%d",l,r,l-r);
                break;
            case 'c':
                sprintf(t,"%d*%d=%d",l,r,l*r);
                break;
        }
        cout<<t<<endl<<strlen(t)<<endl;
    }
    return 0;
}