[CodeM初赛A轮]A

题解

看懂题意题。

#include<cstdio>
#include<algorithm>
#include<cmath>
#define fo(i,a,b) for(i=a;i<=b;i++)
#define fd(i,a,b) for(i=a;i>=b;i--)
using namespace std;
typedef double db;
const int maxn=1000+10;
db c[maxn],d[maxn];
int i,j,k,l,t,n,m;
db u,v,w,ans;
int main(){
    scanf("%d%lf%lf",&n,&v,&u);
    fo(i,1,n) scanf("%lf",&c[i]);
    fo(i,1,n) scanf("%lf",&d[i]);
    fo(i,1,n)
        fo(j,1,n){
            db w=c[i]-(j-1)*d[i]-v;
            ans=ans+u*n/w;
        }
    ans=ans/n;
    printf("%.3lf",ans);
}