Code:
#include iostream
#include cstdio
#include cstring
#include cstdlib
using namespace std;
#define d 256
/*
* search a substring in a string
*/
void search(char *pat, char *txt, int q)
{
int M = strlen(pat);
int N = strlen(txt);
int i, j;
int p = 0;
int t = 0;
int h = 1;
for (i = 0; i < M - 1; i++)
h = (h * d) % q;
for (i = 0; i < M; i++)
{
p = (d *p + pat[i]) % q;
t = (d * t + txt[i]) % q;
}
for (i = 0; i <= N - M; i++)
{
if (p == t)
{
for (j = 0; j < M; j++)
{
if (txt[i + j] != pat[j])
break;
}
if (j == M)
{
cout<<"Pattern found at index: "<
}
}
if (i < N - M)
{
t = (d * (t - txt[i] * h) + txt[i + M]) % q;
if (t < 0)
t = (t + q);
}
}
}
/* Main */
int main()
{
char *txt = "Sanfoundry Linux Training";
char *pat = "nux";
int q = 101;
search(pat, txt, q);
return 0;
}
Output:
Pattern found at index: 13
------------------
(program exited with code: 1)
Press return to continue
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