SUFEQPRE-Suffix Equal Prefix

Suffix Equal Prefix

Given below code is for SUFEQPRE spoj or suffix equal prefix spoj.

Hint :-> Read Z-function . After that this question is just simple implementation of  Z-function.

#include <bits/stdc++.h>
using namespace std;
int Z_function(char s[] , int n)
{
    int z[n+9] , count = 0;
    memset(z , 0 , sizeof z);
    int l=0,r=0;
    z[0] = n;
    for(int i=1;i<n;i++)
    {
        if(i<=r)
            z[i] = min(r-i+1 , z[i-l]);
        while(i+z[i] < n && s[z[i]] == s[i+z[i]])
            z[i]++;
        if(i+z[i]-1 > r)
            l = i, r = i+ z[i] - 1;
        if(z[i] == n - i)
            count ++;
    }
    return count;
}
int main()
{
    int t , n , j = 1;
    char s[1000009];
    scanf("%d ",&t);
    while(t--)
    {
        gets(s);
        n = strlen(s);
        printf("Case %d: %d\n",j,Z_function(s , n));
        j++;
    }
    return 0;
}

FILRTEST-File Recover Testing

File Recover Testing

Below given code is for filrtest spoj or file recover testing spoj.

Hint:-  For solving this question you should Know z-function . If you know z-function of a string then its very to calculate the number of string in given length.

#include <bits/stdc++.h>
using namespace std;
int *Z_function(char s[])
{
    int *z;
    z = (int*)calloc((strlen(s)+9),sizeof(int));
    int l=0,r=0,n = strlen(s);
    z[0] = n;
    for(int i=1;i<n;i++)
    {
        if(i<=r)
            z[i] = min(r-i+1 , z[i-l]);
        while(i+z[i] < n && s[z[i]] == s[i+z[i]])
            z[i]++;
        if(i+z[i]-1 > r)
            l = i, r = i+ z[i] - 1;
    }
    return z;
}
int main()
{
    int n;
    while(1)
    {
        char s[1000009];
        scanf("%d",&n);
        scanf("%s",s);
        if(n==-1)
            return 0;
        int *z;
        int size = strlen(s);
        if(n<size)
        {
            printf("0\n");
            continue;
        }
        z = (int*)calloc((size+9),sizeof(int));
        z = Z_function(s);
        int m = 0;
        for(int i=1;i<size;i++)
        {
            if(i+z[i] == size)
                m = max(m , z[i]);
        }
        int total;
        total = (n-m)/(size - m);
        printf("%d\n",total);
    }
    return 0;
}