Horspool算法

Horspool算法

若文本 S = “FAILUREEISATHEBMOTHERCCFDSUCCESS”，模式P = “SUCCE”，利用Horspool算法给出完整过程。

#include<stdio.h>
#include<string.h>
void setTable(int T[], char s[], char p[])
{
	for (int i = 0; i < 26; i++)
		T[i] = strlen(p);
	for (int i = 0; i < strlen(p);i++)
	{
		if (i != strlen(p) - 1)
		{
			int a1 = p[i] - 65;
			T[a1] = strlen(p) - i - 1;
		}
		else
		{
			int a1 = p[i] - 65;
			T[a1] = strlen(p) ;
		}
	}
}
int horspool(char s[], char p[],int T[])
{
	int flags = strlen(p) - 1;  //代表指向S中的位置
	printf("%d  ", flags);
	while (flags<=strlen(s))
	{
		int k = 0;
		for (int j = strlen(p)-1; j > 0; j--)
		{
			
			if (s[flags - k] != p[j])
			{
				flags += T[s[flags] - 65];
				printf("%d  ", flags);
				break;
			}
			else
			{
				k++;
			}
			if (j <= 1)
				return flags-4;
		}
	}
}
int main()
{
	char s[] = "FAILUREEISATHEBMOTHERCCFDSUCCESS";
	char p[] = "SUCCE";
	int T[26];
	setTable(T, s, p);
	printf("所得的表为：\n");
	for (int i = 0; i < 26; i++)
		printf("%c ", i+65);
	printf("\n");
	for (int i = 0; i < 26; i++)
		printf("%d ", T[i]);
	printf("\n");
	printf("s中flag变化过程：");
	int L = horspool(s, p,T);
	printf("\n");
	printf("匹配成功时S串中首位置： ");
	printf("%d", L);
	printf("\n");
	return 0;
}