using namespace std;
int main(){
	int n; 
    cin >> n; 
    cout << n%10 << n/10%10 << n/100;
    return 0;
}

复制一下吧

#include<bits/stdc++.h> using namespace std; int main() { int n; cin>>n; cout<<n%10<<n/10%10<<n/100; return 0; }