代码：

#include<bits/stdc++.h>
#define ll long long 
#define sort stable_sort
using namespace std;
//writen by DoubleCats
ll n;
string a;
int main(){
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);
	cin>>a;
	if(a=="-0"){
		cout<<0;
		return 0;
	}
	if(a[0]!='-'){
		reverse( a.begin() , a.end() );
	}
	else {
		reverse( a.begin()+1 , a.end() );
	}
	int len=a.size();
	for(int i=0;i<=len-1;i++){
		if(a[i]=='0'&&i!=len-1) continue;
		if(a[i]=='0'&&i==len-1){
			cout<<a[i];
			continue;
		} 
		cout<<a[i];
	}
	
	return 0;
}

记录 #7 #9 #10 WA