Как работает calloc

    f = (int*) calloc(sizeof(float), m);

#include <iostream>
#include <cstring>
#include <cstdlib>
using namespace std;
void PREF(string pattern, int f[])
{
int m = pattern.length(), k; 
f[0] = -1;
    for
    (int i = 1; i < m; i++) {
    k = f[i - 1];
    while (k >= 0) {
        if (pattern [k] == pattern [i-1])
        break;
        else k = f[k];}
    f[i] = k + 1;}
}
bool KMP(string pattern, string target) {
    int m = pattern.length();
    int n = target.length();
    int* f;
    f = (int*) calloc(sizeof(float), m);
    PREF(pattern, f);
    int i = 0;
    int k = 0;
    while (i < n) {
        if (k == -1) {
        i++;
        k = 0;}
    else if
    (target[i] == pattern[k]) {
    i++;
    k++;
        if (k == m)
        return 1;}
        else
        k = f[k];}
    return 0;}
int main()
{
string tar = "ABCAFDFABCAuiHUIIH**(7880BHCeio_ewUBEViwevvwowi&*&*iUGVYikv)// weg ew ABCABDBDhhwig8Mmfgu8";
string pat = "ABCABD";
if (KMP(pat, tar))
cout << "'" << pat << "' found in string '" << tar << "'" << endl;
else
cout << "'" << pat << "' not found in string '" << tar << "'" << endl;
return 0;
}