[ 백준 ] 2342 Dance Dance Revolution

Link | 백준 2342번 문제 : Dance Dance Revolution

📌 Code

GitHub Repository

void solve() throws IOException {
    StringTokenizer tokenizer = new StringTokenizer(reader.readLine());
    int[][][] dp = new int[tokenizer.countTokens()][5][5];
    dp[0][0][0] = 1;
    for (int i = 1; i < dp.length; i++) {
        int target = Integer.parseInt(tokenizer.nextToken());
        for (int r = 0; r < 5; r++) {
            for (int c = 0; c < 5; c++) {
                if (dp[i - 1][r][c] > 0) {
                    if (target != r)
                        dp[i][r][target] = positiveMin(dp[i][r][target], dp[i - 1][r][c] + strength(c, target));
                    if (target != c)
                        dp[i][target][c] = positiveMin(dp[i][target][c], dp[i - 1][r][c] + strength(r, target));
                }
            }
        }
    }
    result.append(Arrays.stream(dp[dp.length - 1]).flatMapToInt(Arrays::stream).filter(i -> i != 0).min().orElseThrow() - 1);
}

int positiveMin(int positiveAndZero, int positiveNum) {
    return positiveAndZero == 0 ? positiveNum : Math.min(positiveAndZero, positiveNum);
}

int strength(int original, int target) {
    return original == target ? 1 : original == 0 ? 2 : Math.abs(original - target) == 2 ? 4 : 3;
}