Hulu面试题解答――N位数去除K个数字

2014-11-24 13:01:42 · 作者: · 浏览: 0

给定一个N位数,例如12345,从里面去掉k个数字,得到一个N-k位的数,例如去掉2,4,得到135,去掉1,5,得到234。设计算法,求出所有得到的N-k位数里面最小的那一个。

写的代码如下,思路是通过堆排序得到N位数里边最大的前K个数,然后按照原数字的顺序去除得到的最大的K个数。感觉写的很乱,可能还有些小问题,鲁棒性应该很差,努力锻炼。。努力提高!

typedef unsigned int uint;
//Heap adjust function
void HeapAdjust(uint *value, uint start, uint end)
{
	for( int i=start; 2*i<=end; )
	{
		uint index = 2*i;
		if(index+1<=end && value[index+1] > value[index])
			index +=1;
		if(value[index] > value[i])
		{
			uint temp = value[i];
			value[i] = value[index];
			value[index] = temp;
		}
			i = index;
	}
}
//Heap creation function
void CreateHeap(uint *value, uint start, uint end)
{
	uint middle = (start+end)/2;
	for( uint i = middle;i>=start;i--)
	{
		HeapAdjust(value, i, end);
	}
}
//Kick K numbers from N
uint KickK(uint N, uint K)
{
	if(N>4294967295)
		return 0;
	uint i,tempN=N;
	uint length=0;
	uint value[10],outValue[10];
	bool flag;
	i = 1;
	//get the numbers of N 
	while(tempN != 0)
	{
		value[i]=tempN%10;
		outValue[i]=value[i];
		tempN=tempN/10;
		i++;
	}
	length = i-1;
	//check the condition
	if(K >= length)
		return 0;
	//Get the K biggest numbers, and store then in the last K positions in array value
	CreateHeap(value,1,length);
	for(i=0;i
  
   =1;i--)
	{
		flag = true;
		for(uint j=length+1-K;j<=length; j++)
		{
			if(outValue[i] == value[j])
				flag = false;
		}
		if(flag)
			printf("%d", outValue[i]);
	}
	return 1;
}

int main()
{
	uint N=61829;
	uint K=3;
	KickK(N,K);
}