软件工程作业-(third)

1.选题目(1) 最大连续子数组和（最大子段和）

问题：给定n个整数（可能为负数）组成的序列a[1],a[2],a[3],…,a[n],求该序列如a[i]+a[i+1]+…+a[j]的子段和的最大值。当所给的整数均为负数时定义子段和为0，依此定义，所求的最优值为： Max{0,a[i]+a[i+1]+…+a[j]},1<=i<=j<=n例如，当（a[1],a[2],a[3],a[4],a[5],a[6]）=(-2,11,-4,13,-5,-2)时，最大子段和为20

2.程序设计和代码

2.1GITHUB代码地址https://github.com/Lpofeng/find_max_add.git

2.2程序流程图

此次采用判定/条件覆盖

2.3核心代码

int find_max_add(vector<int> vec, const int size, int* start, int* end)
{
if (size == 0)
	return -100;
int final_max = vec[0]>0?vec[0]:0;
if (size != 1) {
	int cur_start = 0;
	int cur_end = 0;
	for (int i = 0; i < size; ++i)
	{
		int cur_max = vec[i];
		cur_start = i;
		for (int j = i + 1; j < size; ++j)
		{
			cur_max += vec[j];
			if (cur_max > final_max)
			{
				final_max = cur_max;
				*start = cur_start;
				*end = j;
			}
		}
	}
	if (final_max < vec[size - 1])
	{
		final_max=vec[size - 1];
		*start = size - 1;
	}
}
return final_max;

}

3.测试代码

    TEST_METHOD(TestMethod1)
	{
		int s = 0;
		int e = 0;
		vector<int> v = { -2,-1,-3,5};
		Assert::AreEqual(5,find_max_add(v, 4, &s, &e));
	}
	TEST_METHOD(TestMethod2)
	{
		int s = 0;
		int e = 0;
		vector<int> v = {-3,-1,0,5,99,-150 };
		Assert::AreEqual(104, find_max_add(v, 6, &s, &e));
	}
	TEST_METHOD(TestMethod3)
	{
		int s = 0;
		int e = 0;
		vector<int> v = { -20,-1,30,5,-10,33,-49,-13 };
		Assert::AreEqual(58, find_max_add(v, 8, &s, &e));
	}
	TEST_METHOD(TestMethod4)
	{
		int s = 0;
		int e = 0;
		vector<int> v = { -41,-28,-0,-3,-5,-33,-44,0 };
		Assert::AreEqual(0, find_max_add(v, 8, &s, &e));
	}

4样例测试结果

源代码测试

测试代码