一串首尾相连的珠子(m个)，有N种颜色(N<=10)，设计一个算法，取出其中一段，要求包含所有N中颜色，并使长度最短

#include <iostream>
using namespace std;

#define N 3


bool GetMinlen(int *a,int m,int &shortHead,int & shortlen)
{
	int start=0,end = 0;
	int countColor = 0;
	int *colorArray = new int[N];
	shortlen = m;
	shortHead = 0;

	for(int i =0;i< N;i++)
	{
		colorArray[i] = 0;
	}

	while(start < m)
	{
		//向后搜索直至所有的颜色均出现
		while(countColor < N && (end+1)%m !=start)
		{
			if(colorArray[a[end]]++ == 0)
			{
				countColor++;
			}

			if(countColor <N)
			{
				end=(end+1)%m;
			}
		}


		if(countColor != N)
		{
			cout << "珠子颜色数少于所要找的数目"<<endl;
			return false;
		}

		//start向后移动，直到有一个颜色数为0
		while(start<m)
		{
			if(colorArray[a[start]] > 1)
			{
				colorArray[a[start]]--;
				start++;
			}
			else
			{
				break;
			}
		}

		if(shortlen > end - start +1)
		{
			shortlen = end -start +1;
			shortHead = start;
		}

		colorArray[a[start]]--;
		start++;
		countColor--;
		end = (end+1)%m;
		colorArray[a[end]]++;
	}

	return true;
}



int main()
{
	int start,end;
	int m[] ={0,1,1,1,2,0,1,2,1,2,0};
	GetMinlen(m,11,start,end);
	cout << start << " " <<end<< endl ;
	return 0;
}