【BZOJ】【P2318】【Spoj4060 game with probability Problem】【题解】【概率DP】

传送门:http://www.lydsy.com/JudgeOnline/problem.php?id=2318



Code:

#include<bits/stdc++.h>
using namespace std;
int main(){
int T,n;
double p,q;
static double f[1002],g[1002];
cin>>T;
while(T--){
cin>>n>>p>>q;n=min(n,1000);
p=max(p,1-p);q=max(q,1-q);
f[0]=0;g[0]=1;
for(int i=1;i<=n;i++){
if(f[i-1]>g[i-1])p=1-p,q=1-q;
f[i]=(p*g[i-1]+(1-p)*q*f[i-1])/(1-(1-p)*(1-q));
g[i]=(q*f[i-1]+(1-q)*p*g[i-1])/(1-(1-p)*(1-q));
if(f[i-1]>g[i-1])p=1-p,q=1-q;
}printf("%.6lf\n",f
);
}
return 0;
}