class Solution { public int numTeams(int[] rating) { int[][][] dp = new int[2][3][rating.length]; // base for (int i = 0; i < rating.length; ++i) { dp[0][0][i] = 1; dp[1][0][i] = 1; } for (int count = 2; count <= 3; ++count) { for (int i = 0; i < rating.length; ++i) { for (int j = i + 1; j < rating.length; ++j) { if (rating[i] < rating[j]) { dp[0][count - 1][j] += dp[0][count - 2][i]; } if (rating[i] > rating[j]) { dp[1][count - 1][j] += dp[1][count - 2][i]; } } } } int teams = 0; for (int i = 0; i < rating.length; ++i) { teams += dp[0][2][i] + dp[1][2][i]; } return teams; } }