求数组中连续最大和值，时间复杂度为O(n)

来源：互联网发布：excel怎么找出相同数据编辑：程序博客网时间：2024/05/01 06:53

自己写的，感觉对了，贴出来show。

static int[] GetSequementSumMax(int[] arr)
        {
            int[] arrOld = new int[2];
            int[] arrNew = new int[2];
            int sumMaxOld = 0;
            int sumMaxNew = 0;
            int minusSum = 0;

            for(int i=0;i<arr.Length;i++)
            {
                if (arr[i] < 0 && minusSum < 0 && sumMaxNew > 0)
                {
                    if (sumMaxOld + minusSum + sumMaxNew > sumMaxNew)
                    {
                        arrOld[1] = i-1;
                        sumMaxOld += minusSum + sumMaxNew;
                    }
                    else
                    {
                        sumMaxOld = sumMaxNew;
                        arrOld[0] = arrNew[0];
                        arrOld[1] = arrNew[1];
                    }
                    arrNew[0] = 0;
                    arrNew[1] = 0;
                    minusSum = 0;
                    sumMaxNew = 0;

}

                if (arr[i] > 0 && sumMaxOld == 0)
                {
                    sumMaxOld += arr[i];
                    arrOld[0] = i;
                }
                else if (arr[i] > 0 && sumMaxOld > 0 && minusSum == 0)
                {
                    sumMaxOld += arr[i];
                    arrOld[1] = i;
                }
                else if (arr[i] < 0 && sumMaxOld > 0)
                {
                    minusSum += arr[i];
                }

                if (arr[i] > 0 && minusSum < 0 && sumMaxNew == 0)
                {
                    arrNew[0] = i;
                    sumMaxNew += arr[i];
                }
                else if (arr[i] > 0 && minusSum < 0 && sumMaxNew > 0)
                {
                    arrNew[1] = i;
                    sumMaxNew += arr[i];
                }

                if (i == arr.Length - 1)
                {
                    if (arr[i] > 0 && minusSum<0 && sumMaxOld+minusSum+sumMaxNew>sumMaxNew)
                    {
                        arrOld[1] = i;
                    }
                    else if (arr[i] > 0 && minusSum < 0 && sumMaxOld + minusSum + sumMaxNew < sumMaxNew)
                    {
                        return arrNew;
                    }

                }

            }

return arrOld;

}