USACO21 FEB BRONZE

year_of_the_cow.cpp

#include <iostream>

#include <map>
#include <string>

// Assume Cow B in each line appeared before
class Solution {
public:
    enum class Relation {BEFORE, AFTER};
    enum class Zodiac {
        Rat = 1,   
        Ox,    
        Tiger, 
        Rabbit,
        Dragon,
        Snake, 
        Horse, 
        Goat,  
        Monkey,
        Rooster,
        Dog,   
        Pig
    };
    Solution() {
        birth_year["Bessie"] = 2021;
    };
    void add(const std::string& a, Relation relation, const std::string& zodiac_name, const std::string & b) {
        int gap;
        if (relation == Relation::AFTER) {
            gap = static_cast<int>(zodiac[zodiac_name]) - static_cast<int>(get_zodiac_for(birth_year[b]));
            if (gap <= 0) gap += 12;
            birth_year[a] = birth_year[b] + gap;

        } else if (relation == Relation::BEFORE) {
            gap = static_cast<int>(get_zodiac_for(birth_year[b])) - static_cast<int>(zodiac[zodiac_name]);
            if (gap <= 0) gap += 12;
            birth_year[a] = birth_year[b] - gap;
        }
        
    }
    auto get_from_bessie(const std::string& someone) {
        return birth_year[someone] - birth_year["Bessie"];
    }
private:
    static std::map<std::string, Zodiac> zodiac;
    std::map<std::string, int> birth_year;

    Zodiac get_zodiac_for(int year) {
        int gap = year - 2021; // Year of the Ox
        while (gap > 10) gap -= 12;
        while (gap < -1) gap += 12;
        return static_cast<Zodiac>(gap + 2);
    }
};

std::map<std::string, Solution::Zodiac> Solution::zodiac = {
    {"Rat",     static_cast<Zodiac>(1) },   
    {"Ox",      static_cast<Zodiac>(2) },
    {"Tiger",   static_cast<Zodiac>(3) },   
    {"Rabbit",  static_cast<Zodiac>(4) },   
    {"Dragon",  static_cast<Zodiac>(5) },   
    {"Snake",   static_cast<Zodiac>(6) },   
    {"Horse",   static_cast<Zodiac>(7) },   
    {"Goat",    static_cast<Zodiac>(8) },   
    {"Monkey",  static_cast<Zodiac>(9) },   
    {"Rooster", static_cast<Zodiac>(10)},        
    {"Dog",     static_cast<Zodiac>(11)},    
    {"Pig",     static_cast<Zodiac>(12)}};

int main() {
    Solution inst;
    int n;
    std::cin >> n;
    for (int i = 0; i < n; i++) {
        std::string a, tmp_ , relation, animal, from, b;
        std::cin >> a >> tmp_ >> tmp_ >> relation >> animal >> tmp_ >> tmp_ >> b;
        if (relation == "previous") {
            inst.add(a, Solution::Relation::BEFORE, animal, b);
        } else if (relation == "next") {
            inst.add(a, Solution::Relation::AFTER, animal, b);
        }
    }
    std::cout << std::abs(inst.get_from_bessie("Elsie")) << std::endl;
}

Problems Link: http://www.usaco.org/index.php?page=feb21results