KMP算法--待定

 

https://blog.csdn.net/slimmm/article/details/83989811

KMP算法

 

准备搞压缩看他文章 不清楚干啥的 先放着这

#include <stdio.h>
#include <string.h>//memset
#include <stdlib.h>//free
#include <stddef.h>

#define uint8_t  unsigned char
#define uint16_t unsigned short
#define uint32_t unsigned int
#define uint64_t unsigned long long
#define  uLong unsigned long
typedef unsigned char uchar;
typedef unsigned short ushort;
typedef unsigned int uint;

#define TEST_STR	0	//选择测试对象是字符串还是数组

typedef struct KMP
{
	uchar *src; 	//源数据
	uchar *dst;	    //要求匹配的数据
	ushort sLen;	//源数据长度
	ushort pLen;	//匹配数据长度
	ushort coord;	//匹配到数据记录其坐标
	ushort matchLen; 	//最大的匹配长度
}KMP_TypeDef;

KMP_TypeDef KMP;

bool KMP_Search(KMP_TypeDef *KMP)
{
	int i=0,j=0,max=0,baki=0;
	if(KMP->sLen==0 || KMP->pLen==0)
	{
		return false;
	}	
	while(i < KMP->sLen)
	{	//把源数据遍历一遍
		if(KMP->src[i] == KMP->dst[j]){	//从源数据中找到与匹配数据相同的数据
			i++;
			j++;
			if(j >= max)
			{		
				max = j; 	//更新最长匹配数据长度
				baki = i;	//备份坐标值
			}
		}
		else
		{
			i = i - j + 1;
			j = 0;	//如果失配，则下一次匹配从匹配数据的第一个数据开始
		}
	}
	KMP->coord = baki-max;	//找到最佳匹配数据的下标
	KMP->matchLen = max; 	//匹配数据长度
	return true;
} 

int main(void)
{
	uchar str[100]={0};
	KMP_TypeDef kmp;
#if TEST_STR	
	kmp.src = "a b a c a a b a c a b a c a b a a b b";//"ABCDEFGHIJKLMNOPQRSTUVWXYZd abcdefghijklmnopqrstuvwxyz  ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdesfghijklmnopqrstuvwxyz";//
	kmp.dst = "a b a c a b";//"abcdesfghiu";//
	kmp.sLen = strlen(kmp.src);
	kmp.pLen = strlen(kmp.dst);
	printf("slen:%d - plen:%d\n",kmp.sLen,kmp.pLen);
#else
	uchar arr1[] = {0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f};
	uchar arr2[] = {0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b};
	kmp.sLen = sizeof(arr1)/sizeof(arr1[0]);
	kmp.pLen = sizeof(arr2)/sizeof(arr2[0]);
	kmp.src = (uchar *)malloc(kmp.sLen * sizeof(arr1[0]));
	kmp.dst = (uchar *)malloc(kmp.pLen * sizeof(arr2[0]));
	memcpy(kmp.src, arr1, kmp.sLen); 
	memcpy(kmp.dst, arr2, kmp.pLen);
	printf("slen:%d - plen:%d\n",kmp.sLen,kmp.pLen);
#endif
	KMP_Search(&kmp);
	printf("coord:%d - Len:%d\n",kmp.coord, kmp.matchLen);		//打印下标和长度
	strncpy((char *)str, (char *)kmp.dst, kmp.matchLen);	//字符串拷贝，这里拷贝数据也没出错
	printf("Match: %s\n",str);	//打印字符串，测试数组也将打印成字符串，具体内容可以参照ASCII码表
}

 

来源：CSDN

作者：GKoSon

链接：https://blog.csdn.net/weixin_42381351/article/details/103460762