solution.cpp

#include <bits/stdc++.h>
using namespace std;
class Solution
{
public:
	vector<int> findSubstring(string s, vector<string> &words)
	{
		vector<int> res;
		if (s.empty() || words.empty())
		{
			return res;
		}
		unordered_map<string, int> ht;
		for (const auto &w : words)
		{
			ht[w]++;
		}
		int len = words[0].length();
		for (int i = 0, j = 0; i < s.length() - words.size() * len + 1; i++)
		{
			unordered_map<string, int> counting;
			for (j = 0; j < words.size(); j++)
			{
				string word = s.substr(i + j * len, len);
				if (++counting[word] > ht[word])
				{
					break;
				}
			}
			if (j == words.size())
			{
				res.push_back(i);
			}
		}
		return res;
	}
};