# [LintCode] Twitch Words

### Problem

Our normal words do not have more than two consecutive letters. If there are three or more consecutive letters, this is a tics. Now give a word, from left to right, to find out the starting point and ending point of all tics.

### Example

Given str = "whaaaaatttsup", return [[2,6],[7,9]].

Explanation:
"aaaa" and "ttt" are twitching letters, and output their starting and ending points.
Given str = "whooooisssbesssst", return [[2,5],[7,9],[12,15]].

Explanation:
"ooo", "sss" and "ssss" are twitching letters, and output their starting and ending points.

### Solution

``````
public class Solution {
/**
* @param str: the origin string
* @return: the start and end of every twitch words
*/
public int[][] twitchWords(String str) {
//set two boundaries, one pre value, only move the right boundary
List<List<Integer>> res = new ArrayList<>();
int l = 0, r = 0;
char[] strs = str.toCharArray();
char pre = strs[0];
for (int i = 0; i < strs.length; i++) {
List<Integer> cur = new ArrayList<>();
if (i != 0 && strs[i] != pre) {
if (r-l >= 2) {
}
l = i;
r = i;
pre = strs[i];
} else if (strs[i] == pre) {
r = i;
}
}
//when the last three chars are twitch
if (r-l >= 2) {
List<Integer> cur = new ArrayList<>();
}

int[][] ans = new int[res.size()][2];
for (int i = 0; i < res.size(); i++) {
ans[i][0] = res.get(i).get(0);
ans[i][1] = res.get(i).get(1);
}
return ans;
}
}
``````