1 #include <iostream> 2 #include <algorithm> 3 #include <cstring> 4 #include <cstdio> 5 #include <bitset> 6 #include <vector> 7 #include <queue> 8 #include <stack> 9 #include <cmath> 10 #include <list> 11 #include <set> 12 #include <map> 13 #define rep(i,a,b) for(int i = a;i <= b;++ i) 14 #define per(i,a,b) for(int i = a;i >= b;-- i) 15 #define mem(a,b) memset((a),(b),sizeof((a))) 16 #define FIN freopen("in.txt","r",stdin) 17 #define FOUT freopen("out.txt","w",stdout) 18 #define IO ios_base::sync_with_stdio(0),cin.tie(0) 19 #define mid ((l+r)>>1) 20 #define ls (id<<1) 21 #define rs ((id<<1)|1) 22 #define INF 0x3f3f3f3f 23 using namespace std; 24 typedef long long LL; 25 typedef pair<int, int> PIR; 26 const int N = 6e4+5; 27 28 int n; 29 double x[N], v[N]; 30 bool judge(double md){ 31 double l = 0, r = 1e9*1.0; 32 rep (i, 1, n) { 33 double ll = x[i]-v[i]*md, rr = x[i]+v[i]*md; 34 if(ll < l && ll > r && rr < l && rr > r) return false; 35 l = max(ll, l); 36 r = min(rr, r); 37 if(l > r) return false; 38 } 39 return true; 40 } 41 int main() 42 { 43 //FIN; 44 while (scanf("%d", &n) != EOF) { 45 rep (i, 1, n) scanf("%lf", &x[i]); 46 rep (i, 1, n) scanf("%lf", &v[i]); 47 double low = 0, high = 1e9*1.0, ans = 0; 48 rep (i, 1, 300) { 49 double md = (low+high)/2; 50 if(judge(md)) { high = md-1; ans = md; } 51 else low = md+1; 52 } 53 printf("%.6lf\n", ans); 54 } 55 return 0; 56 }
