// Created by hira #include #include #include #include #include #include using namespace std; // #define LOOPS // #define DEBUG double truncateWithPrecision(double value, int precision) { return (trunc(value * pow(10, precision)) / pow(10, precision)); } double PfromC(double C) { #ifdef DEBUG cout << "C: " << C << "\n"; #endif double pProcOnN = 0; double pProcByN = 0; double sumNpProcOnN = 0; int maxFails = (int)ceil(1 / C); for (int N = 1; N <= maxFails; ++N) { pProcOnN = min(1.0, N * C) * (1 - pProcByN); pProcByN += pProcOnN; sumNpProcOnN += N * pProcOnN; } return ( 1 / sumNpProcOnN ); } double CfromP(double p) { double Cupper = p; double Clower = 0; double Cmid; double p1; double p2 = 1; int runs = 1; while(true) { Cmid = (Cupper + Clower) / 2; p1 = PfromC(Cmid); #ifdef DEBUG cout << "p1: " << p1 << "\n"; cout << "p2: " << p2 << "\n"; cout << "abs: " << abs(p1 - p2) << "\n\n"; #endif // if (truncateWithPrecision(abs(p1 - p2), 6) <= 0) break; if (abs(p1 - p2) <= 0) break; if (p1 > p) { Cupper = Cmid; } else { Clower = Cmid; } p2 = p1; ++runs; } #if defined LOOPS || defined DEBUG cout << "Loops " << runs << " times: "; #endif return Cmid; } int main() { #ifdef DEBUG cout << setprecision (50); #endif double runs = 5; for (int i = 1; i <= runs; i++) { double chance = i*1/runs; cout << "C(" << chance << ") = " << CfromP(chance) << "\n\n"; } return 0; }

C Value - Pseudo Random Distribution Dota 2