分治法求：数列最大子序列，出错，求解，多谢

package com.datastructures.capt0020;    public class MaxSubSum {              private static int maxSumRec(int[] a, int left, int right){          if(left==right)//Base case              if(a[left]>0) return a[left];              else return 0;          int center = (left+right)/2;          int maxLeftSum=maxSumRec(a,left,center);          int maxRightSum=maxSumRec(a,center,right);                    int maxLeftBorderSum = 0, leftBorderSum=0;          for(int i=center;i>=left;i--){              leftBorderSum+=a[i];              if(leftBorderSum>maxLeftBorderSum)                  maxLeftBorderSum = leftBorderSum;          }          int maxRightBorderSum=0, rightBorderSum=0;          for(int i=center+1;i<=right;i++){              rightBorderSum+=a[i];              if(rightBorderSum>maxRightBorderSum)                  maxRightBorderSum=rightBorderSum;          }          return maxLeftSum>maxRightSum?(maxLeftSum>(maxLeftBorderSum+maxRightBorderSum)?maxLeftSum:(maxLeftBorderSum+maxRightBorderSum))                                       :(maxRightSum>(maxLeftBorderSum+maxRightBorderSum)?maxRightSum:(maxLeftBorderSum+maxRightBorderSum));      }      /**      * Driver for divide-andconquer maximum contiguous      * subsequence sum algorithm.      * */            public static int getMaxSubSum3(int [] a){          return maxSumRec(a,0,a.length-1);      }              /**      * @param args      */      public static void main(String[] args) {          int [] a = {1,-1,0,2,9,-4,5,7,2,0};          System.out.println((0+a.length-1)/2);          System.out.println(1/2);            //        //System.out.println(MaxSubSum.getMaxSubSum1(a));  //        System.out.println(MaxSubSum.getMaxSubSum2(a));          System.out.println(MaxSubSum.getMaxSubSum3(a));  //        System.out.println(MaxSubSum.getMaxSubSum4(a));          // TODO Auto-generated method stub        }    }  /*错误信息： * Exception in thread "main" java.lang.StackOverflowError[color=#FF0000]    at com.datastructures.capt0020.MaxSubSum.maxSumRec(MaxSubSum.java:13)    at com.datastructures.capt0020.MaxSubSum.maxSumRec(MaxSubSum.java:17)    at com.datastructures.capt0020.MaxSubSum.maxSumRec(MaxSubSum.java:18)    at com.datastructures.capt0020.MaxSubSum.maxSumRec(MaxSubSum.java:18)[/color] * */