Java 动态规划解题：圆圈取数游戏

import java.util.Scanner;

public class Main {

static int N;
static int[] A;
static int[][] F;

static int DP(int i, int j) {
    if (F[i][j] != -1) {
        return F[i][j];
    }
    if (i == j) {
        return A[i] % 2;
    }
    F[i][j] = Math.max(A[i] % 2 + DP(i + 1, j), A[j] % 2 + DP(i, j - 1));
    return F[i][j];
}

public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    N = input.nextInt();
    A = new int[N];
    F = new int[N][N];
    for (int i = 0; i < N; i++) {
        A[i] = input.nextInt();
    }
    int ans = 0;
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            F[i][j] = -1;
        }
    }
    for (int i = 0; i < N; i++) {
        if (DP((i + 1) % N, (i + N - 1) % N) > (N - 1) / 2) {
            ans++;
        }
    }
    System.out.println(ans);
}

}