Question

Hi everyone I am having a problem trying to get this to work. Basically what I wanted to do is to read a text file containing this kind of data not exactly but just similar and count the frequency of each letter appearing on each line. Also the real data contains any random ASCII from 0-255.

An examples is:

Hi this is john.
We are going .4%2) &,.! m@ll

What I wanted to have is something like this implemented in Lists of Maps

{H=3, i=3, ‘ ‘=3, t=1, h=2, s=2,… until the end of the line },

{W=1, e=2, ‘ ‘=4, a=1, r=1, g=2, o=1, i=1, n=1, .=2, 4=1, %=1…. until the end of line},

so its a Lists of Map

I have tried to research on similar questions but the closest I can do in coding it is this.

List <Map<String, Integer>> storeListsofMaps = new ArrayList<Map<String, Integer>>();
ArrayList <String> storePerLine = new ArrayList<String>();
String getBuf;

try {
FileReader rf = new FileReader("simpleTextCharDist.txt");
BufferedReader encapRF = new BufferedReader(rf);

getBuf = encapRF.readLine();

while (getBuf!=null){
storePerLine.add(getBuf);

getBuf = encapRF.readLine();
}

for (String index: storePerLine){
Map<String, Integer> storeCharAndCount = new HashMap<String, Integer>();

Integer count = storeCharAndCount.get(index);
storeCharAndCount.put(index, (count==null)?count = 1:count+1);

storeListsofMaps.add(storeCharAndCount);
}

System.out.println("StoreListsofMaps: "+ storeListsofMaps);

encapRF.close();
}

I know this code would not execute the one I described but am stuck up until this part. The code I have shown will only count the word itself not each letter in the string. I tried counting iterating over each element in the string by converting the string into char [] and converting it back to string again, but it is very inefficient and produces alot of errors. Hope anyone would be kind enough to help.

Answer 1

Here is the pseudo algo to achieve this –

1. Using file I/O create a list containing 1 line as 1 element in the list
2. Write a small helper function which will:
   1. take String (representing an element from list created in step 1)
   2. iterate through the line
   3. create a map of char & count. This map should be the return type.
3. Create a Map<String,Map<String,Int>> where 1st String is the “Line1”, “Line2”, etc. 2nd String is the char value. The Map written inline is the map returned from Step 2.

This should work.