Language: C++

# define _CRT_SECURE_NO_WARNINGS 1
# define _USE_MATH_DEFINES
# include <iostream>
# include <numeric>
# include <string>
# include <bitset>
# include <vector>
# include <algorithm>
# include <cstdlib>
# include <cstdio>
# include <cstring>
# include <cstdlib>
# include <iomanip>
# include <queue>
# include <sstream>
# include <unordered_set>
# include <unordered_map>
# include <climits>
# include <complex>
# include <cmath>
# include <list>
# include <functional>
# include <string>
# include <ctime>
# include <set>
# include <forward_list>
# include <map>
# include <stack>
using namespace std;
# define MP make_pair
# define INF ((int)(1<<25))
# define REP(i,n) for(int i=0;i<(int)n;i++)
# define FOR(i,n) REP(i,n)
# define FORI(i,k,n) for(int i=k;i<(int)n;i++)
# define TORAD 2.0*M_PI/360.0
# define INT(x) int x;cin>>x;
# define STRING(x) string x;cin>>x;
# define STR(x) STRING(x);
# define DOUBLE(x) double x;cin>>x;
# define DBL(x) DOUBLE(x); 
# define ALL(x) begin(x),end(x)
# define RALL(x) (x).rbegin(),(x).rend()
# define DEBUG(x) cout<<#x<<":"<<x<<endl
# define INIT(a) memset(a,-1,sizeof a)
# define CLR(a) memset(a,0,sizeof a)
# define EPS 1e-12
#ifdef _MSC_VER
#include <intrin.h>
#define __builtin_popcount __popcnt
#endif
typedef long long lint;
typedef vector<bool> vb;
typedef vector<char> vc;
typedef vector<int> vi;
typedef vector<lint> vl;
typedef vector<string> vs;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef pair<int, pii> piii;
//const int dx[4] = { 0,1,0,-1 }, dy[4] = { -1,0,1,0 };
//const int M = 1000000007;
template<class T> void debug(T a) { for ( auto i : a )cout << i << endl; }

#define int long long

unordered_multimap<int, pii> ms;

int compute_hash(vs A, vs B, unordered_multimap<int, pii> &m)
{
	vvi hashes;
	int B1 = 9973, B2 = 100000007;

	FOR(i, A.size())
	{
		int t1 = 1;
		FOR(j, B[0].size())t1 *= B1;
		int ah = 0;
		FOR(j, B[0].size())ah = ah*B1 + A[i][j];
		vi h;
		for ( int j = 0; j + B[0].size() <= A[i].size(); j++ )
		{
			h.push_back(ah);
			if ( j + B[0].size() < A[i].size() )ah = ah*B1 + A[i][j + B[0].size()] - A[i][j] * t1;
		}
		hashes.push_back(h);
	}
	FOR(j, hashes[0].size())
	{
		int t2 = 1;
		FOR(i, B.size())t2 *= B2;
		int ah = 0;
		FOR(i, B.size())ah = ah*B2 + hashes[i][j];
		for ( int i = 0; i + B.size() <= hashes.size(); i++ )
		{
			m.insert(MP(ah, pii(j, i)));
			if ( j + B.size() < hashes.size() )ah = ah*B2 + hashes[i][j + B.size()] - hashes[i][j] * t2;
		}
	}

	vi b;
	FOR(i, B.size())
	{
		int t1 = 1;
		int bh = 0;
		FOR(j, B[i].size())bh = bh*B1 + B[i][j];
		b.push_back(bh);
	}
	int ans = 0;
	FOR(i, b.size())
		ans = ans*B2 + b[i];
	return ans;
}

signed main()
{
	string a, b;
	cin >> a >> b;
	vs A(1, a), B(1, b);
	int h=compute_hash(A, B, ms);
	auto i = ms.lower_bound(h), j = ms.upper_bound(h);
	for ( ; i != j; i++ )
	{
		cout << i->second.first << endl;
	}

}

Compiler output:
a.cc: In function 'int main()':
a.cc:120:21: error: 'class std::unordered_multimap<long long int, std::pair<int, int> >' has no member named 'lower_bound'
  120 |         auto i = ms.lower_bound(h), j = ms.upper_bound(h);
      |                     ^~~~~~~~~~~
a.cc:121:22: error: 'j' was not declared in this scope
  121 |         for ( ; i != j; i++ )
      |                      ^