P2394-yyy loves Chemistry I

Posted 2022-12-16 asurudo

 1 #include <iostream>
 2 #define _for(i,a,b) for(int i = (a);i < b;i ++)
 3 #define _rep(i,a,b) for(int i = (a);i > b;i --)
 4 #define INF 0x3f3f3f3f
 5 #define MOD 1000000007
 6 #define maxn 50003
 7 typedef long long ll;
 8 
 9 using namespace std;
10 typedef pair<int,int> P;//first 是最短距离，second 是顶点编号
11 inline ll read()
12 
13     ll ans = 0;
14     char ch = getchar(), last = ‘ ‘;
15     while(!isdigit(ch)) last = ch, ch = getchar();
16     while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - ‘0‘, ch = getchar();
17     if(last == ‘-‘) ans = -ans;
18     return ans;
19 
20 inline void write(ll x)
21 
22     if(x < 0) x = -x, putchar(‘-‘);
23     if(x >= 10) write(x / 10);
24     putchar(x % 10 + ‘0‘);
25 
26 long double rnt = 0.0;
27 long double a;
28 int main()
29 
30     scanf("%15Lf",&a);
31     a *= 100000000;
32     printf("%.8Lf",a/2300000000);
33     return 0;
34