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POMerge sort on structs not working
 

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  1. POMerge sort on structs not working
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    <p>I am performing a merge sort on a struct. The sort is performed on the destination cities which is an array When I tried it with plain arrays it worked.It doesnt work for structures though :(</p> <pre><code>#include &lt;fstream&gt; // for std::ifstream #include &lt;sstream&gt; // for std::istringstream #include &lt;cstring&gt; // for std::string and std::getline #include &lt;iostream&gt; #include &lt;ctype.h&gt; #include &lt;stdio.h&gt; #include&lt;algorithm&gt; #include &lt;string.h&gt; using namespace std; #define MAX 30 #define WORD 3 typedef struct node{ int nodeId; char destCity[MAX]; char arrCity[MAX]; int time; }NODE; typedef struct edge{ int adjoin; int distance; }EDGE; typedef struct graph{ NODE cityNode[MAX]; EDGE e[MAX][MAX]; }GRAPH; GRAPH graph,graphCpy,Temp; GRAPH currentArray; void MergeA(int low ,int mid , int high) { int i = low, j = mid+1 , k = low; while(i &lt;= mid &amp;&amp; j &lt;= high) { if(currentArray.cityNode[i].destCity &lt;= currentArray.cityNode[j].destCity) { strcpy(Temp.cityNode[k].destCity,currentArray.cityNode[i].destCity); i++; } else { strcpy(Temp.cityNode[k].destCity,currentArray.cityNode[j].destCity); Temp[k].assign(currentArray[j]); j++; } k++; } if(i &gt; mid ) { for(int h = j ;h &lt;= high ; h++ ) { strcpy(Temp.cityNode[k].destCity,currentArray.cityNode[h].destCity); k++; } } else for(int h = i; h&lt;= mid ; h++ ) { strcpy(Temp.cityNode[k].destCity,currentArray.cityNode[h].destCity); k++; } for(int i = low; i &lt;= high ; i++){ strcpy(currentArray.cityNode[i].destCity,Temp.cityNode[i].destCity); } } void MergeSortA(int low , int high) { int mid = 0; if(low &lt; high) { mid = low + (high-low)/2; cout&lt;&lt;"beforemerge"&lt;&lt;endl; MergeSortA(low , mid); MergeSortA(mid+1,high); MergeA(low,mid,high); } } int main(){ std::ifstream infile("theWords.txt"); std::string line; while (std::getline(infile,(line)) &amp;&amp; count&lt;30){ std::istringstream iss(line); if ((iss) &gt;&gt;graph.cityNode[count].destCity &gt;&gt; graph.cityNode[count].arrCity &gt;&gt; graph.cityNode[count].time){ graph.cityNode[count].nodeId = count ; count++; } graphCpy= graph; currentArray= graphCpy; MergeSortA(0,count); for(int i = 0; i &lt;= count ; i++){ cout &lt;&lt; currentArray.cityNode[i].destCity &lt;&lt;endl; } } </code></pre> <p>I input values into graph copy which is then given to currentArray!!</p>
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    1. USuser2803194
    1. USuser2803194
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    1. COWhat did you discover when you tried to debug the program? Step through it like by line comparing the values in memory against what you think they should be.
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      1. USRaymond Chen
    2. COTHe problem was when I tried it with an array it sorts it fine with the logic. Just when I convert it to a struct it didnt sort but gave me the unsorted input
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      1. USuser2803194
    3. COYou don't show us how you populate `graphCpy`. Is a [minimal complete example](http://sscce.org) too much to ask?
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      1. POMerge sort on structs not working
      1. USBeta
 

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