PrimeSoccer.cpp

class PrimeSoccer {
public:
    using LL = long long;
    LL C(int n, int m){
        LL ans = 1L;
        for(int i=1;i<=m;++i)
            ans *= n--;
        for(int i=1;i<=m;++i)
            ans /= i;
        return ans;
    }

    double getProbability(int skillOfTeamA, int skillOfTeamB) {
        vector<int> aWin = {2,3,5,7,11,13,17};
        double reta = 0.0, retb = 0.0, pa = skillOfTeamA/100.0, pb = skillOfTeamB/100.0;
        for(int d : aWin)
            reta += pow(pa, d)*pow((1-pa),(18-d))*C(18, d);
        for(int d : aWin)
            retb += pow(pb, d)*pow((1-pb),(18-d))*C(18, d);
        return reta+retb-(reta*retb);
    }
};