Solution.java

class Solution {
    public long getMaxFunctionValue(List<Integer> receiver, long k) {
        int n = receiver.size(), m = 64 - Long.numberOfLeadingZeros(k);
        int[][] f = new int[n][m];
        long[][] g = new long[n][m];
        for (int i = 0; i < n; ++i) {
            f[i][0] = receiver.get(i);
            g[i][0] = i;
        }
        for (int j = 1; j < m; ++j) {
            for (int i = 0; i < n; ++i) {
                f[i][j] = f[f[i][j - 1]][j - 1];
                g[i][j] = g[i][j - 1] + g[f[i][j - 1]][j - 1];
            }
        }
        long ans = 0;
        for (int i = 0; i < n; ++i) {
            int p = i;
            long t = 0;
            for (int j = 0; j < m; ++j) {
                if ((k >> j & 1) == 1) {
                    t += g[p][j];
                    p = f[p][j];
                }
            }
            ans = Math.max(ans, p + t);
        }
        return ans;
    }
}