HDOJ 2087

思路： KMP

#include<stdio.h>
#include<string.h>
char a[1005], b[1005];
int fail[1005];
int lena, lenb;
int cnt;
void getfail()
{
fail[0] = -1;
int i, j;
for(i = 1, j = -1; i < lenb; i ++)
{
while(j >= 0 && b[j + 1] != b[i])
{
j = fail[j];
}
if(b[j + 1] == b[i])
j ++;
fail[i] = j;
}
return ;
}

void kmp()
{
getfail();
int i, j;
for(i = 0, j = 0; i < lena; i ++)
{
while(j && b[j] != a[i])
{
j = fail[j - 1] + 1;
}
if(b[j] == a[i])
j ++;
if(j == lenb)
{
cnt ++;
if(i + lenb < lena)
j = 0;
else
return ;
}
}
}
int main(int argc, char const *argv[])
{
while(~scanf("%s", a) && strcmp(a, "#"))
{
scanf("%s", b);
lena = strlen(a);
lenb = strlen(b);
cnt = 0;
kmp();
printf("%d\n", cnt);
memset(a, 0, sizeof(a));
memset(b, 0, sizeof(b));
}
return 0;
}