TIL 220825

알고리즘

프로그래머스

1. Level 1 체육복

function solution(n, lost, reserve) {
    const newLost = lost.filter(element => reserve.includes(element) === false).sort((a, b) => a - b);
    const newReserve = reserve.filter(element => lost.includes(element) === false).sort((a, b) => a - b);
    
    newReserve.forEach((element) => {
        let index1;
        let index2;
        if ((index1 = newLost.indexOf(element - 1)) !== -1) {
            newLost.splice(index1, 1);
            
            return;
        }
        
        if ((index2 = newLost.indexOf(element + 1)) !== -1) {
            newLost.splice(index2, 1);
            
            return;
        }
    })
    
    return n - newLost.length;
}

2. Level 2 가장 큰 수

function solution(numbers) {
    let newNumbers = [...numbers].map(element => String(element));
    newNumbers.sort((a, b) => (b + a) - (a + b));

//     if (newNumbers.every(element => element === '0')) {
//         return '0';
//     }
    
//     return newNumbers.join('');
    
    if (newNumbers[0] === '0') {
        return '0';
    }
    
    return newNumbers.join('');
}

3. Level 2 가장 큰 정사각형 찾기

function solution(board) {
    let maxValue = 0;
    const dp = new Array();
    dp.push(new Array(board[0].length + 1).fill(0));
    
    board.forEach((element) => {
        element.unshift(0);
        dp.push(element);
    })
    
    for (let i = 1; i < dp.length; i++) {
        for (let j = 1; j < dp[0].length; j++) {
            if (dp[i][j] !== 0) {
                dp[i][j] = Math.min(dp[i - 1][j - 1], dp[i - 1][j], dp[i][j - 1]) + 1;
                
                if (maxValue < dp[i][j]) {
                    maxValue = dp[i][j];
                }
            }
        }
    }
    
    return maxValue * maxValue;
}

4. Level 1 최대공약수와 최소공배수

function solution(n, m) {
    const realN = n;
    const realM = m;
    let GCD;
    let LCM;
    
    while (n !== 0 && m !== 0) {
        if (n > m) {
            n %= m;
            continue;
        }
        
        if (m > n) {
            m %= n;
            continue;
        }
    }
    
    n === 0 ? GCD = m : GCD = n;
    LCM = realN * realM / GCD;
    
    return [GCD, LCM];
}

5. Level 1 완주하지 못한 선수

function solution(participant, completion) {
    const hash = new Object();
    
    participant.forEach((element) => {
        if (hash[element] === undefined) {
            hash[element] = 0;
        }
        
        hash[element] += 1;
    })
    
    completion.forEach((element) => {
        hash[element] -= 1;
    })
    
    for (let key of Object.keys(hash)) {
        if (hash[key] !== 0) {
            return key;
        }
    }
}

6. Level 1 예산

function solution(d, budget) {
    let count = 0;
    let current = 0;
    const newD = [...d];
    newD.sort((a, b) => a - b);
    
    newD.forEach((element) => {
        if (current + element <= budget) {
            current += element;
            count += 1;
        }
    })
    
    return count;
}