一様乱数だけあるときのおみくじプログラム

plain_omikuji.cpp

#include <iostream>
#include <random>

int main()
{
    std::vector<int> prob = {1, 9, 25, 25, 30, 9, 1};
    const std::string str[] = {"大吉", "中吉", "小吉", "吉末", "吉", "凶", "大凶"};
    std::mt19937 rng;

    //出現確率を累積に変換
    int acc = 0;
    for(auto p = prob.begin(); p != prob.end(); ++p)
        acc = *p = acc + *p;

    //おみくじを引きまくる
    while(1)
    {
        const int t = rng() % 100;
        for(auto p = prob.begin(); p != prob.end(); ++p)
        {
            if(t < *p)
            {
                std::cout << str[p - prob.begin()] << std::endl;
                break;
            }
        }
    }
}