java - How to count same words in a string and get the index of the first word that is equal? -

my task create static method named "dupwords" gets strings parameter , returns how many times word @ same string. catch is, need return two-dimensional array, have 2 columns , rows how many different sub strings in string...

for example: "abcd xyz abcd abcd def xyz"

this pairs [0][3] [5][2] [19][01] first pair means word "abcd" appears 3 times , state @ index 0 (and rest..)

this image of two-dimensional array: (the text in hebrew can see drawing)

i started something...you think way off :/ (its start) think didn't understand how deal two-dimensional array..

public static int[][] dupwords (string str) {          string [] stringarray = str.split(" ");         int countwords = 0;         int index = 0;         int [][] retarr;          (int = 0; < stringarray.length; i++) {             (int j = 0; j < stringarray.length; j++) {                 if (stringarray[i].equalsignorecase(stringarray[j])){                     countwords++;                     index = stringarray[i].indexof(str);                  }             }         }     } 

please help, thankss

find number of unique words.

you can it, putting words stringarray hashmap. hashmap come handy later.

create array retarr = new int[unique][2];

complete solution below (beware, didn't compile it!)

public static int[][] dupwords (string str) {      string [] stringarray = str.split(" ");     int countwords = 0;     int index = 0;     hashmap<string, integer> indexmap = new hashmap<string, integer>();     hashmap<string, integer> countmap = new hashmap<string, integer>();      int index = 0;     (int = 0; < stringarray.size(); i++) {        string s = stringarray[i];        if (!indexmap .containskey(s)) {          indexmap.put(s, index);          countmap.put(s, 1);        }        else {          int cnt = countmap.get(s);          countmap.put(s, cnt+1);        }        index += s.length() + 1;     }      int [][] retarr = new int[map.size()][2];      (int = 0; < stringarray.size(); i++) {        string s = stringarray[i];        retarr[i][0] = indexmap.get(s);        retarr[i][1] = countmap.get(s);     }      return retarr; } 

now, without hashmap, or other dynamic structure it's quite difficult do. easiest approach create bigger necessary array , @ end trim it. this.

public static int[][] dupwords (string str) {      string [] stringarray = str.split(" ");     int countwords = 0;     int index = 0;      int [][] retarr = new int[stringarray.size()][2];      int uniqewords = 0;     (int = 0; < stringarray.size(); i++) {        string s = stringarray[i];        if (s != null) {          retarr[uniquewords][0] = str.indexof(s);          int cnt = 1;          (int j = + 1; j < stringarray.size(); j++) {            if (s.equalsignorecase(stringarray[j])) {              stringarray[j] = null;              cnt++;            }          }          retarr[uniquewords][1] = cnt;          uniquewords++;        }     }      int[][] newretarr = new int[uniquewords][2];     (int = 0; < uniquewords; i++) {       newretarr[i][0] = retarr[i][0];       newretarr[i][1] = retarr[i][1];     }      return newretarr; }