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Checks if a given hand is a valid Mahjong hand
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| #include "CheckValidity.h" | |
| #include <iostream> | |
| using namespace std; | |
| int main() { | |
| vector<int> hand = {1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 6}; | |
| string validHand = (isValidHand(hand)) ? "true" : "false"; | |
| cout << "Hand is valid: " << validHand << endl; | |
| return 0; | |
| } | |
| bool isValidHand(vector<int> hand) { | |
| // Get the possible pair value | |
| vector<int> pairPossibleValue; | |
| int remainder = getSum(&hand) % 3; | |
| if (remainder == 0) | |
| pairPossibleValue = {3, 6, 9}; | |
| else if (remainder == 1) | |
| pairPossibleValue = {2, 5, 8}; | |
| else if (remainder == 2) | |
| pairPossibleValue = {1, 4, 7}; | |
| // Remove the pair from hand, if the pair is in the hand | |
| vector<vector<int>> handsWithPairRemoved; | |
| for (int value : pairPossibleValue) { | |
| auto handWithPairRemoved = removeValue(hand, value); | |
| if (handWithPairRemoved) | |
| handsWithPairRemoved.push_back(*handWithPairRemoved); | |
| } | |
| // Check if the remaining hand can form triplets | |
| for (vector<int> h : handsWithPairRemoved) | |
| if (checkRemaining(h)) // If any one of the remaining hands are valid, then the hand is valid | |
| return true; | |
| // None of the hands with pair removed are valid, so return false | |
| return false; | |
| } | |
| int getSum(vector<int>* const hand) { | |
| int sum; | |
| for (int i : *hand) | |
| sum += i; | |
| return sum; | |
| } | |
| optional<vector<int>> removeValue(vector<int> hand, int value) { | |
| int numRemoved = 0; | |
| for (auto it = hand.begin(); it != hand.end(); ) { | |
| if (numRemoved == 2) | |
| break; | |
| if (*it == value) { | |
| hand.erase(it); | |
| numRemoved++; | |
| } else it++; | |
| } | |
| if (numRemoved < 2) | |
| return nullopt; | |
| return hand; | |
| } | |
| bool checkRemaining(vector<int> hand) { | |
| for (auto it = hand.begin(); it != hand.end(); ) { | |
| if (hand.empty()) | |
| return true; | |
| if (it + 2 == hand.end()) | |
| break; | |
| int curPos = *it; | |
| int posOne = *(it + 1); | |
| int posTwo = *(it + 2); | |
| // Check if there are pong or chi and remove them if so | |
| if (curPos == posOne && posOne == posTwo) { | |
| hand.erase(it + 2); | |
| hand.erase(it + 1); | |
| hand.erase(it); | |
| } else if (curPos == posOne - 1 && posOne == posTwo - 1) { | |
| hand.erase(it + 2); | |
| hand.erase(it + 1); | |
| hand.erase(it); | |
| } else it++; // Increment one if no patterns found | |
| } | |
| // If valid, triplets would all be removed, leaving empty hand | |
| return hand.empty(); | |
| } |
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| #pragma once | |
| #include <vector> | |
| #include <optional> | |
| bool isValidHand(std::vector<int> hand); | |
| int getSum(std::vector<int>* const hand); | |
| std::optional<std::vector<int>> removeValue(std::vector<int> hand, int value); | |
| bool checkRemaining(std::vector<int> hand); |
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