连续子数组的最大和

输入一个整型数组，数组里有正数也有负数，数组中一个或者连续的多个整数组成一个子数组。求所有子数组和的最大值，要求时间复杂度为O(n)

int FindGreatestSumOfSubArray(int *pData, int nLength){       assert (pData == NULL || nLength <= 0);       int nCurSum = 0;       int nGreatestSum = 0x80000000;       for (int i = 0; i < nLength; ++i)       {             if (nCurSum <= 0)                   nCurSum = pData[i];            else                  nCurSum += pData[i];            if (nCurSum > nGreatestSum)                  nGreatestSum = nCurSum;      }      return nGreatestSum;}