Bzoj 3925: [Zjoi2015] After the earthquake fantasy Township (probability)

CLJ is like out of the CTSC on the things, it seems to have to find time to take his several problems to do

First of all, F (x) is the probability of the answer >x, so it's the answer to get this thing from 0 to 1 points.

F (x) <=> edge less than x probability that the graph can not be connected

This is a bit difficult to find, consider the probability of the graph

Remember F (s) for the probability of the set S Unicom, then F (s) =1-sigma (f (S ') * (1-x) ^cnt) (s ' s ' belongs to the and S ' must contain a point k,cnt for the number of sides of the link s ' with CS s ')

It can be found that f (s) is a polynomial and it can be integral.

Since still useless on the 64-bit evaluation system, double or not, had to use __float128, relatively slow

CODE:

#include <cstdio>#include<iostream>#include<cstring>#include<algorithm>#include<vector>using namespacestd;typedef Vector<__float128>Ploy;ployoperator+(ploy X,ploy y) {ploy ans (max (x.size (), Y.size ()),0);  for(intI=0; I<ans.size (); i++) {        if(I<x.size ()) ans[i]+=X[i]; if(I<y.size ()) ans[i]+=Y[i]; }    returnans;} Ployoperator-(ploy X,ploy y) {ploy ans (max (x.size (), Y.size ()),0);  for(intI=0; I<ans.size (); i++) {        if(I<x.size ()) ans[i]+=X[i]; if(I<y.size ()) ans[i]-=Y[i]; }    returnans;} Ployoperator*(ploy X,ploy y) {ploy ans (x.size ()+y.size ()-1,0);  for(intI=0; I<x.size (); i++)          for(intj=0; J<y.size (); j + +) Ans[i+j]+=x[i]*Y[j]; returnans;}BOOLb[1040];p Loy f[1040],quick[ -];intn,m;structedges{intx, y;} e[ -];p Loy One (1,1); inlinevoidprint (ploy x) {printf ("%d\n", X.size ());  for(intI=0; I<x.size (); i++) printf ("%LF",Double(X[i])); printf ("\ n");}voiddpintx) {    if(B[x])return ; B[X]=1; Ploy TMP (0,0);  for(intI=1;i< (1&LT;&LT;N); i++) {        if(! (i&1))Continue; if((i&x)!=i)Continue; if(i==x)Continue; intj=x^i; intCnt=0;  for(intk=1; k<=m*2; k++)             if(i& (1<<e[k].x) &&j& (1&LT;&LT;E[K].Y)) cnt++;        DP (i); TMP=tmp+f[i]*quick[cnt]; } F[x]=one-tmp;} __float128 Cal (ploy x) {__float128 ans=0;  for(intI=0; I<x.size (); i++) ans+=x[i]*1.0/(i+1); returnans;}intMain () {scanf ("%d%d",&n,&m); quick[0]=One ; quick[1]=ploy (2,0); quick[1][0]=1; quick[1][1]=-1;  for(intI=2; i<=m;i++) quick[i]=quick[i-1]*quick[1];  for(intI=1; i<=m;i++) {        intx, y; scanf ("%d%d",&x,&y); X--, y--; E[i*2-1]=(edges) {x, y}; E[i*2]=(edges) {y,x}; } b[1]=1; f[1]=One ; DP ((1<<n)-1); Ploy ans=one-f[(1<<n)-1]; printf ("%.6lf\n",Double(Cal (ANS))); return 0;}

Bzoj 3925: [Zjoi2015] After the earthquake fantasy Township (probability)