leetcode GuessNumberHigherorLowerII
z
 2019-04-09 10:36:27   
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public class GuessNumberHigherorLowerII {
  /**
   * We are playing the Guess Game. The game is as follows:
   *
   * I pick a number from 1 to n. You have to guess which number I picked.
   *
   * Every time you guess wrong, I'll tell you whether the number I picked is higher or lower.
   *
   * However, when you guess a particular number x, and you guess wrong, you pay $x. You win the game when you guess the number I picked.
   *
   * Example:
   *
   * n = 10, I pick 8.
   *
   * First round:  You guess 5, I tell you that it's higher. You pay $5.
   * Second round: You guess 7, I tell you that it's higher. You pay $7.
   * Third round:  You guess 9, I tell you that it's lower. You pay $9.
   *
   * Game over. 8 is the number I picked.
   *
   * You end up paying $5 + $7 + $9 = $21.
   * Given a particular n ≥ 1, find out how much money you need to have to guarantee a win.
   */
  public  int getMoneyAmount(int n) {
    int[][] dp = new int[n+1][n+1];
    int ans = Integer.MAX_VALUE;
    return helper(dp, 1, n);
  }

  public  int helper(int[][] dp, int left, int right){
    if (dp[left][right] != 0) return dp[left][right];
    if (left >= right) return 0;
    int min = Integer.MAX_VALUE;
    for (int i=left; i<=right; i++){
      int temp = i + Math.max(helper(dp, left, i-1), helper(dp, i+1, right));
      min = Math.min(temp, min);
    }
    dp[left][right] = min;
    return min;
  }
  public static void main(String[] args){
  }
}