题解 100% AC

#include <bits/stdc++.h>
using namespace std;
int main(){
    int a,b;cin>>a>>b;
    double c=b*6.0,d=(a*30.0)+(b*0.5),ans=abs(d-c);
    if(ans>180)ans=360-ans;
    cout<<fixed<<setprecision(2)<<ans;
    return 0;
}