给定一个整数数组 nums，下面代码找到一个具有最大和的连续子数组，并返回该最大和。则下面说法错误的是（ ）。
int crossSum(vector<int>& nums, int left, int mid, int right) {
int leftSum = INT_MIN, rightSum = INT_MIN;
int sum = 0;
for (int i = mid; i >= left; i--) {
sum += nums[i];
leftSum = max(leftSum, sum);
}
sum = 0;
for (int i = mid + 1; i <= right; i++) {
sum += nums[i];
rightSum = max(rightSum, sum);
}
return leftSum + rightSum;
}
int helper(vector<int>& nums, int left, int right) {
if (left == right)
return nums[left];
int mid = left + (right - left) / 2;
int leftMax = helper(nums, left, mid);
int rightMax = helper(nums, mid + 1, right);
int crossMax = crossSum(nums, left, mid, right);
return max({leftMax, rightMax, crossMax});
}
int maxSubArray(vector<int>& nums) {
return helper(nums, 0, nums.size() - 1);
}
- A. 上述代码采用分治算法实现
- B. 上述代码采用贪心算法
- C. 上述代码时间复杂度为
- D. 上述代码采用递归方式实现