软工第三次作业

一、题目要求

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。

二、编写代码

代码地址：https://git.dev.tencent.com/j673679968/ruangongdisancizuoye.git

#include<stdio.h>
#include<stdlib.h>
int MaxSubseqSum(int a[], int n)
{
int i, j, thissum = 0, maxsum = 0;
for (i = 0; i < n; i++)
{
thissum = 0;
for (j = i; j < n; j++)
{

thissum += a[j];

if (thissum > maxsum)
{
maxsum = thissum;
}
}
}
return maxsum;
}

int main()
{
int a[100], n, i, m;
scanf_s("%d", &n);
for (i = 0; i < n; i++)
{
scanf_s("%d", &a[i]);
}
m = MaxSubseqSum(a, n);
printf("%d", m);
system("pause");
return 0;
}

三、代码流程图

四、测试代码

1、输入整数n<0.
2、整数元素均为负数.
3、整数元素均为正数.
4、最大子段和在后.
5、最大子段和在前.

#include "stdafx.h"
#include "CppUnitTest.h"
#include"../软工2/test.h"

using namespace Microsoft::VisualStudio::CppUnitTestFramework;

namespace UnitTest1
{
TEST_CLASS(UnitTest1)
{
public:
TEST_METHOD(TestMethod1)
{
int a[] = { 0 };
int n = -1;
Assert::AreEqual(MaxSubseqSum(a, n), 0);
}
TEST_METHOD(TestMethod2)
{
int a[] = { -1,-2,-3,-4. - 5 };
int n = 5;
Assert::AreEqual(MaxSubseqSum(a, n), 0);
}
TEST_METHOD(TestMethod3)
{
int a[] = { 1,2,3,4,5 };
int n = 5;
Assert::AreEqual(MaxSubseqSum(a, n), 15);
}
TEST_METHOD(TestMethod4)
{
int a[] = { 4,5,-6,-7,10 };
int n = 5;
Assert::AreEqual(MaxSubseqSum(a, n), 10);
}
TEST_METHOD(TestMethod5)
{
int a[] = { 4,5,-6,-7,8 };
int n = 5;
Assert::AreEqual(MaxSubseqSum(a, n), 9);
}
};
}

五、单元测试结果