#include<bits/stdc++.h>//万能头//iostream using namespace std; int main() { int a,b; scanf("%3d%1d",&a,&b); //printf("%.2f"); cout<<b<<a; /** float a; //cin>>a; scanf("%d",&a); //a保留两位小数 cout<<fixed<<setprecision(2); //fixed 告诉计算机输出格式 2 cout<<a; //printf("%.2f",a);//"%d",a(int) "%f",a{float) "%lf",a(double) "%lld",a(long long) //"%c",a(char) "%s",a(char) //cout<<a; //默认输出小数点后五位**/ return 0; }