java算法 蓝桥杯 摆花

package 蓝桥杯java算法训练;

import java.util.Scanner;

public class _5摆花 {
	//动态规划问题，设f[i][j]是前i种花摆放j盆的方案，则f[i][j]=f[i-1][j-k]
   public static void main(String[] args) {
	  Scanner scanner = new Scanner(System.in);
	  int n = scanner.nextInt();//n种花
	  int m = scanner.nextInt();//共m盆
	  int[] a = new int[n+1];
	  int[][] f = new int[n+1][m+1] ;
	  for (int i = 1; i <= n; i++) {
		a[i] = scanner.nextInt();
	  }
	  //前1种花，摆放a[1]盆就一种方案
	  for (int i = 1; i <= a[1]; i++) {
		f[1][i] = 1;
	  }
	  //前i中花，摆放0盆就一种方案
	  for (int i = 1; i <= n; i++) {
		f[i][0] = 1;
	}
	  //前i种花，摆放j盆共f[i][j]=f[i][j]+f[i-1][j-k]种
	  for (int i = 2; i <= n; i++) {
		 for (int j = 1; j <= m; j++) {
			for (int k = 0; k <= a[i]&&k<=j; k++) {
				f[i][j]=f[i][j]+f[i-1][j-k];
				f[i][j] = f[i][j] % 1000007;
			}
		}
	}
	  System.out.println(f[n][m]);
	  
   }
}