<p>Given a string <code>s</code> and a dictionary of strings <code>wordDict</code>, return <code>true</code> if <code>s</code> can be segmented into a space-separated sequence of one or more dictionary words.</p>

<p><strong>Note</strong> that the same word in the dictionary may be reused multiple times in the segmentation.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;leetcode&quot;, wordDict = [&quot;leet&quot;,&quot;code&quot;]
<strong>Output:</strong> true
<strong>Explanation:</strong> Return true because &quot;leetcode&quot; can be segmented as &quot;leet code&quot;.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;applepenapple&quot;, wordDict = [&quot;apple&quot;,&quot;pen&quot;]
<strong>Output:</strong> true
<strong>Explanation:</strong> Return true because &quot;applepenapple&quot; can be segmented as &quot;apple pen apple&quot;.
Note that you are allowed to reuse a dictionary word.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;catsandog&quot;, wordDict = [&quot;cats&quot;,&quot;dog&quot;,&quot;sand&quot;,&quot;and&quot;,&quot;cat&quot;]
<strong>Output:</strong> false
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 300</code></li>
	<li><code>1 &lt;= wordDict.length &lt;= 1000</code></li>
	<li><code>1 &lt;= wordDict[i].length &lt;= 20</code></li>
	<li><code>s</code> and <code>wordDict[i]</code> consist of only lowercase English letters.</li>
	<li>All the strings of <code>wordDict</code> are <strong>unique</strong>.</li>
</ul>

class Solution {
private:
    bool calculate(string& s, int index, int currLength, string temp, unordered_map<string, int>& wordMap, vector<vector<int>>& dp) {
        if(index >= s.length()) return currLength == s.length();
        if(dp[index][currLength] != -1) return dp[index][currLength];
        string newTemp = temp + s[index];
        bool includeEl = false;
        bool notIncludeEl = false;
        if(wordMap.find(newTemp) != wordMap.end()) {
            includeEl = calculate(s, index+1, currLength+newTemp.length(), "", wordMap, dp);
        }
        notIncludeEl = calculate(s, index+1, currLength, newTemp, wordMap, dp);
        return dp[index][currLength] = includeEl | notIncludeEl;
    }
public:
    bool wordBreak(string s, vector<string>& wordDict) {
        int size = s.length();
        int dSize = wordDict.size();
        unordered_map<string, int> wordMap;
        vector<vector<int>> dp(size, vector<int>(size, -1));
        for(auto it: wordDict) wordMap[it] = it.length();
        bool result = calculate(s, 0, 0, "", wordMap, dp);
        return result;
    }
};
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