kmp_function.cpp

vector<int> kmp(string s, string p){
    vector<int> ans;
    auto pi = getPi(p);
    int n = (int)s.size(), m = (int)p.size(), j =0;
    for(int i = 0 ; i < n ; i++){
        while(j>0 && s[i] != p[j])
            j = pi[j-1];
        if(s[i] == p[j]){
            if(j==m-1){
                ans.push_back(i-m+1);
                j = pi[j];
            }else{
                j++;
            }
        }
    }
    return ans;
}