为什么只有70分？

#include <cstdlib>
#include <iostream>
#include <cstring>
using namespace std;
#define MAXN 10000
string s;
int  c, a, t;
int main() 
{ 
    cin>>s;
    a = -1;
    for(int i = 0; i < s.size(); i++) {
        if( s[i]<'0' || s[i] > '9')  a = i;
    }
    if(a == -1) {
      for(int i = s.size() - 1; i >= 0; i--) {
        cout<<s[i];
      }    
    }
    else {
        for(int i = a-1;i>=0;i--) {
            if(s[i] != '0') {cout<<s[i];t++;}
            if(t == 0 && i == 0) cout<<"0";
        }
        cout<<s[a];t = 0;
        for(int i = s.size() - 1;i>a;i--) {
            if(s[i] != '0') {cout<<s[i];t++;}
            if(t == 0 && i == a+1) cout<<"0";
        }
    }
    return 0;
}