Va 12585 poker End Games

Alice and Bob are playing games again !!!! In the beginning, the former has a Yuan, and the latter has B yuan. Each time you play, the probability that each person wins is half-open. If C is the minimum value of A and B, then each time you play, if anyone loses, the winner is C yuan. Ask Alice the probability of winning and the expected number of game disks!

Thought: It looks like it will be iterated! The formula is not good... The probability of discovery is 0.5, and the error range is 1e-5. The probability is negligible as long as it reaches a certain depth!

    #include <iostream>#include <cstdio>#include <cstring>#include <vector>#include <string>#include <algorithm>#include <queue>#include <set>#include <map>using namespace std;typedef long long LL;#define REP(_,a,b) for(int _ = (a); _ <= (b); _++)int a,b;int gcd(int a,int b) {    if(!b) return a;    else return gcd(b,a%b);}double dfs(int x,int y,int dep) {    if(dep > 30 || x==0) return 0.0;    if(y==0) return 1;    if(x > y) {        return dfs(x-y,y*2,dep+1)/2+dfs(x+y,0,dep+1)/2;    }else{        return dfs(0,y+x,dep)/2+dfs(x+x,y-x,dep+1)/2;    }}double dfs1(int x,int y,int dep) {    if(dep > 30) return 1;    if(x==0) return 0;    if(y==0) return 0;    if(x > y) {        return 1+dfs1(x-y,y*2,dep+1)/2;    }else{        return 1+dfs1(x*2,y-x,dep+1)/2;    }}int main(){    int ncase,T=1;    cin >> ncase;    while(ncase--) {        scanf("%d%d",&a,&b);        if(a==b) {            printf("Case %d: 1.000000 0.500000\n",T++);        }else{            int g = gcd(a,b);            int t1 = a/g;            int t2 = b/g;            double p = dfs(t1,t2,0);            double e = dfs1(t1,t2,1);            printf("Case %d: %.6lf %.6lf\n",T++,e,p);        }    }    return 0;}

Va 12585 poker End Games