整型数组处理算法（十一）请实现一个函数：线段重叠。[风林火山]

请实现一个函数：线段重叠; 
输入多个一维线段,求出这些线段相交的所有区域(也用线段表示);  
一条线段用两个值表示(x0,x1), 其中x1>x0;  
比如：输入线段数组[(2,4),(1.5,6),(0.5,3.5),(5,7),(7.5,9)], 

输出线段数组[(1.5,4),(5,6)]

实现代码如下：

float** GetSegmentOverlap(float** array, int nCount,int& OutCount)
{
	int i;
	float* temp = new float[nCount * 2];  
	int* count = new int[nCount * 2];  

	memset(temp, 0, nCount * 2 *sizeof(float));
	int nTotalData = 0;
	for (i = 0; i < nCount; i++) 
	{  
		for (int j = 0; j < 2; j++)
		{  
			//temp[i * 2 + j] =  array[i][j];

			//这里进行排序
			InsertData(temp, array[i][j], ++nTotalData);

			count[i * 2 + j] =0;
		}  
	}
/*
	for (i=0; i< (nCount * 2); i++)
	{
		cout << temp[i] << ",";
	}
	cout << endl;
*/
	//Arrays.sort(temp);

	float x = 0.0;  
	float y = 0.0;  
	for (i = 0; i < nCount; i++) 
	{  
		x = array[i][0];  
		for (int j = 1; j < nCount; j++) 
		{  
			y = array[i][j];  
			for (int k = 0; k < nCount * 2; k++) 
			{  
				//if (temp[k] >= x && temp[k] < y)  
				if (temp[k] > x && temp[k] < y)  
				++count[k];  
			}  
		}  
	}  

	list<int*> resultList; 
	int flag = 0;  
	for (i = 0; i < nCount * 2; i++) 
	{  
		//if (count[i] > 1 && flag == 0) 
		if (count[i] == 1 && flag == 0)
		{  
			flag = 1;  
			resultList.push_back(new int(i));
			
		} 
		else if (count[i] > 1 && flag == 1) 
		{  
		} 
		else if (count[i] == 1 && flag == 1) 
		{  
			flag = 0;  
			resultList.push_back(new int(i)); 
			
		}  
	}  

	list<int*>::iterator itorResultList;

	int k =resultList.size()-1;
	int* j;
	if (resultList.size() > 0) 
	{  
		OutCount = resultList.size()/2;
		float** result = new float* [OutCount];
		for (int m=0; m<OutCount; m++)
		{
			result[m] = new float[2];//new float
		}

		for (itorResultList = resultList.begin(); itorResultList != resultList.end(); itorResultList++) 
		{  
			//for (int j = 0; j < list.size(); j++) 
			//{  
			//	result[i][j] = list.get(j);  
			//}  

			j = *itorResultList;
			//cout << (*j) << ", ";
			result[k/2][k%2] = temp[*j];
			k--;

			//cout << temp[*j] << "," ;

			//释放内存delete *itorResultList;*itorResultList=NULL;,这样是有问题的。
			delete j;
			j=NULL;
		}  

		delete[] temp;
		temp=NULL;
		delete[] count;
		count=NULL;
			
		return result;  
	} 
	else  
	{
		delete[] temp;
		temp=NULL;
		delete[] count;
		count=NULL;
		return NULL;
	}
}

/*按降序排列数组*/
int InsertData(float* a, float nValue, int nCount)
{
	for (int i=0; i<nCount; i++)
	{
		if (a[i]<nValue)
		{
			for (int j=nCount-1; j>i; j--)
			{
				a[j]=a[j-1];
			}
			
			a[i]=nValue;
			
			break;//跳出循环
		}
	}
	return 0;
}

有兴趣的朋友可以自己测试一下，仅提供参考。

此算法有点问题，当有相同起点的时候，完善版明天发布。

整型数组处理算法（十一）请实现一个函数：线段重叠(性能优化)。[风林火山]

转载请注明原创链接：http://blog.youkuaiyun.com/wujunokay/article/details/12586443