标签:sizeof while 成功 scan 测试 dba pre sys lib
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <malloc.h>
//以下为KMP算法
void get_next(char * T, int next[]) //修正前的next数组
{
int i = 1, j = 0;
next[0] = -1;
next[1] = 0;
int m = strlen(T);
while (i<strlen(T) - 1)
{
if (j == -1 || T[j] == T[i])
{
++i;
++j;
next[i] = j;
}
else j = next[j];
}
}
void get_nextval(char * T, int nextval[]) //修正后的nextval数组
{
int i = 1, j = 0;
nextval[0] = -1;
nextval[1] = 0;
int m = strlen(T);
while (i<strlen(T) - 1)
{
if (j == -1 || T[j] == T[i])
{
++i;
++j;
if (T[i] != T[j]) nextval[i] = j;
else nextval[i] = nextval[j];
}
else j = nextval[j];
}
}
int Index_KMP(char * S, char * T, int pos, int next[]) //逐项比较
{
int j = 0, i = pos, lens = strlen(S), lent = strlen(T);
get_next(T, next);
while (i < lens && j < lent)
{
if (S[i] == T[j] || j == -1)
{
i++; j++;
}
else j = next[j];
}
if (j >= lent) return i - lent;
else return -1;
}
//以下为BF算法
int Pos_BF(char * S, char * T)
{
int pos = 1;
for (int i = 0; i < strlen(S); i++)
{
if (S[i] == T[0])
return pos;
else
pos++;
}
return 0;
}
int Index_BF(char * S, char * T)
{
int i = 0, j = 0;
int lens = strlen(S), lent = strlen(T);
while (i <= lens -1 && j <= lent -1 )
{
if (S[i] == T[j])
{
++i;
++j;
}
else
{
i = i - j + 1;
j = 0;
}
}
//跳出循环有两种可能,i=lens说明已经遍历完主串,匹配失败;j=lent,说明子串遍历完成,在主串中成功匹配
if (j == lent) {
return i - lent + 1;
}
//运行到此,为i==lens的情况
return -1;
}
int main()
{
//char *S = "adbadabbaabadabbadada", *T = "adabbadada";
char S[30];
char T[20];
printf("请输入两个字符串进行匹配:\n");
printf("请输入母串:");
scanf("%s", S);
printf("请输入匹配串:");
scanf("%s", T);
//此处开始测试KMP算法
printf("\n**********************KMP算法**************************\n");
int m;
int *next = (int *)malloc((strlen(T) + 1)*sizeof(int)); //修正前的next数组
int *nextval = (int *)malloc((strlen(T) + 1)*sizeof(int)); //修正后的nextval数组
get_next(T, next);
printf("修正前next数组为:");
for (m = 0; m<strlen(T); m++)
{
printf("%d ", next[m] + 1);
}
get_nextval(T, nextval);
printf("\n修正后的nextval数组为:");
for (m = 0; m<strlen(T); m++)
{
printf("%d ", nextval[m] + 1);
}
int t1 = Index_KMP(S, T, 0, nextval);
if (t1 == -1) printf("\n无匹配项!\n");
else
{
printf("\n在第%d项开始匹配成功\n", t1 + 1);
}
//此处开始测试BF算法
printf("\n**********************BF算法**************************\n");
int t2 = Index_BF(S, T);
printf("\n在第%d项开始匹配成功\n", t2);
system("pause");
return 0;
}
标签:sizeof while 成功 scan 测试 dba pre sys lib
原文地址:https://www.cnblogs.com/zhengyu-ahu/p/12038827.html