1주차 (07/01) - Class 2

2798 - 블랙잭

#include <iostream>
#include <vector>

using namespace std;

int main() {
    int cardNum, limitScore, maxScore = 0;
    vector<int> cardList;
    
    cin >> cardNum >> limitScore;

    for (int i=0; i<cardNum; i++) {
        int card;
        cin >> card;

        cardList.push_back(card);
    }

    for (int i=0; i<cardNum-2; i++) {
        for (int j=i+1; j<cardNum-1; j++) {
            for (int k=j+1; k<cardNum; k++) {
                int cardSum = cardList[i] + cardList[j] + cardList[k];

                if (cardSum <= limitScore && cardSum > maxScore) 
                    maxScore = cardSum;
            }
        }
    }

    cout << maxScore << "\n";

    return 0;
}

15829 - Hashing

#include <iostream>
#include <string>

using namespace std;

int main() {
    int strLength;
    string inputStr;
    long long result = 0;
    long long primeNum = 1;

    cin >> strLength >> inputStr;

    for (int i = 0; i < strLength; i++) {
        int alphabetNum = inputStr[i] - 'a' + 1;

        result += alphabetNum * primeNum;
        result %= 1234567891;

        primeNum *= 31;
        primeNum %= 1234567891;
    }

    cout << result << "\n";

    return 0;
}

1259 - 팰린드롬수

#include <iostream>
#include <string>

using namespace std;

int main() {
    while (true) {
        int num;
        string numToStr;
        bool isPalindrome = true;
        
        cin >> num;
        
        if (num == 0)
            break;

        numToStr = to_string(num);

        for (int i=0; i<(numToStr.length() >> 1); i++) {
            int idxFront = i;
            int idxBack  = numToStr.length() - i - 1;

            if (numToStr[idxFront] != numToStr[idxBack]) {
                isPalindrome = false;
                break;
            }
        }

        cout << ((isPalindrome) ? "yes" : "no") << "\n";
    }

    return 0;
}

2609 - 최대공약수와 최소공배수

#include <iostream>
#include <numeric>

using namespace std;

int main() {
    int num1, num2;

    cin >> num1 >> num2;
    
    cout << gcd(num1, num2) << "\n" << lcm(num1, num2);
    
    return 0;
}

---

#include <iostream>

using namespace std;

int main() {
    int num1, num2;
    int gcd, lcm;

    cin >> num1 >> num2;

    if (num1 < num2) 
        swap(num1, num2);

    for (int i = num1; i >= 1; i--) {
        if (num1 % i == 0 && num2 % i == 0) {
            gcd = i;
            break;
        }
    }

    lcm = num1 * num2 / gcd;

    cout << gcd << "\n" << lcm;
    
    return 0;
}

2775 - 부녀회장이 될테야

#include <iostream>

using namespace std;

int main() {
    int testCase;

    cin >> testCase;

    for (int i=0; i<testCase; i++) {
        int floor, roomNumber;
        long long result = 1;

        cin >> floor >> roomNumber;

        for (int i = floor + roomNumber; i >= 2; i--) {
            result *= i;

            if (i <= roomNumber - 1)
                result /= i;

            if (i <= floor + 1)
                result /= i;
        }

        cout << result << "\n";
    }
    
    return 0;
}