简单的几道算法_AboutString

#include<iostream>
#include<list>
#include<string>
using namespace std;

//字符串排序
void Permutation(char *pStr,char *pBegin)
{
	if(*pBegin == '\0')
		cout<<pStr<<endl;

	for(char *pCh = pBegin; *pCh != '\0';++pCh)
	{
		char temp = *pCh;
		*pCh = *pBegin;
		*pBegin = temp;

		Permutation(pStr,pBegin+1);

		temp = *pCh;
		*pCh = *pBegin;
		*pBegin = temp;
	}
}
void Permutation(char *pStr)
{
	if(pStr == NULL)
		return;
	Permutation(pStr,pStr);
}

//字符串组合
void Combination(char *pStr,char *pBegin,unsigned int length,list<char> &listChar)
{
	if(length == 0)
	{
		for(list<char>::iterator iter = listChar.begin();iter != listChar.end();++iter)
			cout<<*iter<<" ";
		cout<<endl;
	}

	else
	{
		for(char *pCh = pBegin; *pCh != '\0';++pCh)
		{
			//cout<<*pCh<<" ";
			listChar.push_back(*pCh);
			Combination(pStr,pCh+1,length-1,listChar);
			listChar.pop_back();
		}
	}
		
}
void Combination(char *pStr)
{
	if(pStr == NULL)
		return;

	unsigned int length = strlen(pStr);
	list<char> listChar;
	for(int i = 1; i <= length; ++i)
	{
		Combination(pStr,pStr,i,listChar);
	}
}

//八皇后问题
void Permutation(char *pStr,char *pBegin,int data[])
{
	if(*pBegin == '\0')
	{
		for(int i = 0; i < 8; i++)
			data[i] = pStr[i] - '0';

	//	int j;
		bool flag = true;
		for(i = 0; i < 8 && flag == true; ++i)
		{
			for(int j = i+1;j < 8;++j)
			{
				if(data[i] - data[j] == j - i || data[i] - data[j] == i - j )
				{
					flag = false;
					break;
				}
			}
			
		}

		if(flag)
		{
			for(int k = 0; k < 8;++k)
				cout<<data[k]; 
			cout<<endl;
		}
	
	}
	//	cout<<pStr<<endl;



	for(char *pCh = pBegin; *pCh != '\0';++pCh)
	{
		char temp = *pCh;
		*pCh = *pBegin;
		*pBegin = temp;

		Permutation(pStr,pBegin+1,data);

		temp = *pCh;
		*pCh = *pBegin;
		*pBegin = temp;
	}
}
void EigthQueens()
{
	int rowIndex[8];
	char num[] = "01234567";
	Permutation(num,num,rowIndex);

}

//字符串的快速排序
const int MAXLENGTH = 100;
int Partition(char *pStr[],int low,int high)
{
	char *pKey = new char(MAXLENGTH);
	strcpy(pKey,pStr[low]);
	
	
	while(low<high)
	{
	while(low < high && strcmp(pKey,pStr[high]) <= 0)
		high--;
//	strcpy(pStr[low],pStr[high]);
	swap(pStr[high],pStr[low]);

	while(low < high && strcmp(pKey,pStr[low]) >= 0)
		low++;
//	strcpy(pStr[high],pStr[low]);
	swap(pStr[high],pStr[low]);

	}

	return low;

}
void StringQucik(char *pStr[],int low,int high)
{
//	int low = 0;
//	int high = length
	if(low < high)
	{
		int index = Partition(pStr,low,high);
		StringQucik(pStr,low,index-1);
		StringQucik(pStr,index+1,high);
	}
}

void getNext(int next[],char *p)
{
	int j = 0;
	int k = -1;
	next[0] = -1;
	while(j < strlen(p)-1)
	{
		if(k == -1 || p[j] == p[k])
		{
			j++;
			k++;
			next[j] = k;
		}
		else
			k = next[k];
	}
}

//KMP模式匹配算法
int KMP(char *tx,char *p,int next[])
{
	int i = 0;
	int j = 0;
	int txLen = strlen(tx);   
	int pLen = strlen(p); 
	//不能直接在while循环用strlen()，这样，如果编译器没有优化，每次都会执行一次strlen()，效率低，
	//其次，strlen返回的是无符号，当j = -1时，与无符号整数比较，－1会自动转换为无符号。因此发生错误。
	while(i < txLen && j < pLen)
	{
		if(j == -1 || tx[i] == p[j])
		{
			i++;
			j++;
		}
		else
			j = next[j];
	}
	if(j == pLen)
		return i - j;
	else
		return -1;
}
int KMP(char *tx, char *p)
{
	int pLen = strlen(p);
	int *next = new int[pLen];
	getNext(next,p);
	return KMP(tx,p,next);
}

//最长的公共连续字符串
int GetLengthofContinusString_DP(char *pText,char *pQuery)
{
	if(pText == NULL || pQuery == NULL)
		return 0;

	int result = 0;
	unsigned int txtLen = strlen(pText);
	unsigned int queryLen = strlen(pQuery);
	int **dp = new int*[txtLen+1];
	for(int n = 0; n <= txtLen;++n)
		dp[n] = new int[queryLen+1];

	for(int i = 0; i <= txtLen; ++i)
		dp[i][0] = 0;
	for(int j = 0; j <= queryLen; ++j)
		dp[0][j] = 0;

	for(i = 1; i<=txtLen; ++i)
	{
		for(j = 1; j <= queryLen;++j)
		{
			if(*(pText+i-1) == *(pQuery+j-1))
			{
				dp[i][j] = dp[i-1][j-1] + 1;
				if( dp[i][j] > result)
					result = dp[i][j];
			}
			else
				dp[i][j] = 0;
		}
	}
	

	return result;
}
void main()
{
//	char str[] = "abc";
//	Combination(str);
//	EigthQueens();
	char *p[] = {"a","ab","aa","dbb",""};
//	int high = strlen(p);
	StringQucik(p,0,5);
	for(int i = 0; i<5;++i)
	{
		cout<<p[i]<<endl;
	}
	
	string str[] = {"afa","Dfeqe","D","dwwf"};
	//int si = str.size();
//	strlen(str);
/*
	cout<<sizeof(str)/sizeof(str[0])<<endl;
	int a[100]= {3,232,242,2,24,2};
	cout<<sizeof(a)/sizeof(a[0])<<endl;
	char *txt = "abcabcdefabcef";
	char *ptxt = "abced";
	cout<<KMP(txt,ptxt)<<endl;
*/
	char *text = "afbckowfsfaf";
	char *query = "ewljeifsf";
	cout<<GetLengthofContinusString_DP(text,query)<<endl;
}