Dyd's Blog

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luoguP7113 [NOIP2020] 排水系统

不开int128见祖宗

排水系统

水题,但是感觉对分数的处理可能会用,记一下

记得开 int128

代码

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#include <bits/stdc++.h>
#define pb push_back
using I128 = __int128;
using namespace std;
const int N = 1e5 + 100;
int n, m;
I128 gcd(I128 x, I128 y){ return (!y) ? (x) : (gcd(y, x % y)); }
struct Fen
{
I128 p, q;
Fen operator + (Fen y)
{
I128 _p = p * y.q + y.p * q, _q = q * y.q;
I128 d = gcd(_p, _q);
_p /= d, _q /= d;
return {_p, _q};
}
Fen operator / (I128 y)
{
I128 d = gcd(y, p);
I128 _p = p / d;
y /= d;
I128 _q = q * y;
return {_p, _q};
}
} a[N];
std::vector<int> to[N];
std::queue<int> q;
int du[N];
void wt(I128 x)
{
if (x < 0) putchar('-'), x = -x;
if (x > 9) wt(x / 10);
putchar(x % 10 + 48);
}
int main()
{
scanf("%d %d", &n, &m);
for (int i = 1, d; i <= n; ++i)
{
scanf("%d", &d);
for (int j = 1, t; j <= d; ++j)
{
scanf("%d", &t);
to[i].pb(t), ++du[t];
}
}
for (int i = 1; i <= n; ++i) a[i] = {0, 1};
for (int i = 1; i <= m; ++i) a[i] = {1, 1}, q.push(i);
while (!q.empty())
{
int x = q.front(); q.pop();
if (!to[x].size()) continue;
a[x] = a[x] / to[x].size();
for (int y : to[x])
{
a[y] = a[y] + a[x];
if (!(--du[y])) q.push(y);
}
}
for (int i = 1; i <= n; ++i) if (!to[i].size()) wt(a[i].p), putchar(' '), wt(a[i].q), putchar('\n');
return 0;
}