<p>You are given two <strong>0-indexed</strong> strings <code>source</code> and <code>target</code>, both of length <code>n</code> and consisting of <strong>lowercase</strong> English letters. You are also given two <strong>0-indexed</strong> character arrays <code>original</code> and <code>changed</code>, and an integer array <code>cost</code>, where <code>cost[i]</code> represents the cost of changing the character <code>original[i]</code> to the character <code>changed[i]</code>.</p>

<p>You start with the string <code>source</code>. In one operation, you can pick a character <code>x</code> from the string and change it to the character <code>y</code> at a cost of <code>z</code> <strong>if</strong> there exists <strong>any</strong> index <code>j</code> such that <code>cost[j] == z</code>, <code>original[j] == x</code>, and <code>changed[j] == y</code>.</p>

<p>Return <em>the <strong>minimum</strong> cost to convert the string </em><code>source</code><em> to the string </em><code>target</code><em> using <strong>any</strong> number of operations. If it is impossible to convert</em> <code>source</code> <em>to</em> <code>target</code>, <em>return</em> <code>-1</code>.</p>

<p><strong>Note</strong> that there may exist indices <code>i</code>, <code>j</code> such that <code>original[j] == original[i]</code> and <code>changed[j] == changed[i]</code>.</p>

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

<pre>
<strong>Input:</strong> source = &quot;abcd&quot;, target = &quot;acbe&quot;, original = [&quot;a&quot;,&quot;b&quot;,&quot;c&quot;,&quot;c&quot;,&quot;e&quot;,&quot;d&quot;], changed = [&quot;b&quot;,&quot;c&quot;,&quot;b&quot;,&quot;e&quot;,&quot;b&quot;,&quot;e&quot;], cost = [2,5,5,1,2,20]
<strong>Output:</strong> 28
<strong>Explanation:</strong> To convert the string &quot;abcd&quot; to string &quot;acbe&quot;:
- Change value at index 1 from &#39;b&#39; to &#39;c&#39; at a cost of 5.
- Change value at index 2 from &#39;c&#39; to &#39;e&#39; at a cost of 1.
- Change value at index 2 from &#39;e&#39; to &#39;b&#39; at a cost of 2.
- Change value at index 3 from &#39;d&#39; to &#39;e&#39; at a cost of 20.
The total cost incurred is 5 + 1 + 2 + 20 = 28.
It can be shown that this is the minimum possible cost.
</pre>

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

<pre>
<strong>Input:</strong> source = &quot;aaaa&quot;, target = &quot;bbbb&quot;, original = [&quot;a&quot;,&quot;c&quot;], changed = [&quot;c&quot;,&quot;b&quot;], cost = [1,2]
<strong>Output:</strong> 12
<strong>Explanation:</strong> To change the character &#39;a&#39; to &#39;b&#39; change the character &#39;a&#39; to &#39;c&#39; at a cost of 1, followed by changing the character &#39;c&#39; to &#39;b&#39; at a cost of 2, for a total cost of 1 + 2 = 3. To change all occurrences of &#39;a&#39; to &#39;b&#39;, a total cost of 3 * 4 = 12 is incurred.
</pre>

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

<pre>
<strong>Input:</strong> source = &quot;abcd&quot;, target = &quot;abce&quot;, original = [&quot;a&quot;], changed = [&quot;e&quot;], cost = [10000]
<strong>Output:</strong> -1
<strong>Explanation:</strong> It is impossible to convert source to target because the value at index 3 cannot be changed from &#39;d&#39; to &#39;e&#39;.
</pre>

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

<ul>
	<li><code>1 &lt;= source.length == target.length &lt;= 10<sup>5</sup></code></li>
	<li><code>source</code>, <code>target</code> consist of lowercase English letters.</li>
	<li><code>1 &lt;= cost.length == original.length == changed.length &lt;= 2000</code></li>
	<li><code>original[i]</code>, <code>changed[i]</code> are lowercase English letters.</li>
	<li><code>1 &lt;= cost[i] &lt;= 10<sup>6</sup></code></li>
	<li><code>original[i] != changed[i]</code></li>
</ul>

class Solution:
    def minimumCost(self, source: str, target: str, original: List[str], changed: List[str],
                    cost: List[int]) -> int :
        costs = dict()
        originalSet = set()
        changedSet = set()
        for i in range(0, len(original)) :
            if original[i] not in costs :
                costs[original[i]] = dict()
            if changed[i] in costs[original[i]]:
                costs[original[i]][changed[i]] = min(costs[original[i]][changed[i]], cost[i])
            else:
                costs[original[i]][changed[i]] = cost[i]
            originalSet.add(original[i])
            changedSet.add(changed[i])
        originalList = list(originalSet)
        changesList = list(changedSet)
        # print(str(originalList))
        # print(str(changesList))
        
        arr = [[float("inf") for _ in range(len(changesList))] for _ in range(len(originalList))]
        origCharMap = dict()
        changesCharMap = dict()
        #print(costs)
        for i in range(0, len(originalList)) :
            for j in range(0, len(changesList)) :
                if changesList[j] in costs[originalList[i]] :
                    arr[i][j] = costs[originalList[i]][changesList[j]]
                if changesList[j] == originalList[i] :
                    arr[i][j] = 0
                changesCharMap[changesList[j]] = j
            
            origCharMap[originalList[i]] = i
        #print(str(changesList)+". "+ str(originalList))
        #print(arr)
        for k in range(0, len(changesList)) :
            for i in range(0, len(originalList)) :
                for j in range(0, len(changesList)) :
                    if changesList[k] in origCharMap:
                        p = origCharMap[changesList[k]]
                        arr[i][j] = min(arr[i][j], arr[i][k] + arr[p][j])
                    else :
                        arr[i][j] = min(arr[i][j], sys.maxsize)

        sum = 0
        # print(origCharMap)
        # print(changesCharMap)
        print(arr)
        for i in range(0, len(source)) :
            if source[i] == target[i]:
                continue
            if source[i] not in origCharMap or target[i] not in changesCharMap:
                return -1
            r = origCharMap[source[i]]
            c = changesCharMap[target[i]]
            if arr[r][c] == float("inf"): 
                return -1
            else :
                sum += arr[r][c]
        return sum
          

          
        
        
936