| # | Title | Solutions | Time | Space | Difficulty | Tag | Notes

|-----|----------------|---------------|---------------|---------------|-------------|--------------|-----

|557|[Reverse Words in a String III](https://leetcode.com/problems/reverse-words-in-a-string-iii/)|[Solution](../../master/leetcode-algorithms/src/main/java/com/stevesun/solutions/ReverseWordsinaStringIII.java) | O(n) |O(n) | Easy | String

|556|[Next Greater Element III](https://leetcode.com/problems/next-greater-element-iii/)|[Solution](../../master/leetcode-algorithms/src/main/java/com/stevesun/solutions/NextGreaterElementIII.java) | O(n)|O(1)| Medium | String

|554|[Brick Wall](https://leetcode.com/problems/brick-wall/)|[Solution](../../master/leetcode-algorithms/src/main/java/com/stevesun/solutions/BrickWall.java) | O(n) (n is total number of bricks in the wall) |O(m) (m is width of the wall) | Medium | HashMap

|551|[Student Attendance Record I](https://leetcode.com/problems/Student Attendance Record I/)|[Solution](../../master/leetcode-algorithms/src/main/java/com/stevesun/solutions/StudentAttendanceRecordI.java) | O(n)| O(1) | Easy| String

|549|[Binary Tree Longest Consecutive Sequence II](https://leetcode.com/problems/binary-tree-longest-consecutive-sequence-ii/)|[Solution](../../master/leetcode-algorithms/src/main/java/com/stevesun/solutions/BinaryTreeLongestConsecutiveSequenceII.java) | O(n) |O(n) | Medium | Tree

|548|[Split Array with Equal Sum](https://leetcode.com/problems/split-array-with-equal-sum/)|[Solution](../../master/leetcode-algorithms/src/main/java/com/stevesun/solutions/SplitArraywithEqualSum.java) | O(n^2) |O(1) | Medium | Array

|547|[Friend Circles](https://leetcode.com/problems/friend-circles/)|[Solution](../../master/leetcode-algorithms/src/main/java/com/stevesun/solutions/FriendCircles.java) | O(n^2) |O(n) | Medium | Union Find

packagecom.stevesun.solutions;

publicclassStudentAttendanceRecordI {

publicbooleancheckRecord(Strings) {

intaCount =0;

for (inti =0;i <s.length();i++) {

if (s.charAt(i) =='A') {

aCount++;

if (aCount >1)returnfalse;

}elseif (s.charAt(i) =='L') {

intcontinuousLCount =0;

while (i <s.length() &&s.charAt(i) =='L') {

i++;

continuousLCount++;

if (continuousLCount >2)returnfalse;

}

i--;

}

}

returntrue;

}

}

packagecom.stevesun;

importcom.stevesun.solutions.StudentAttendanceRecordI;

importorg.junit.Before;

importorg.junit.BeforeClass;

importorg.junit.Test;

importstaticjunit.framework.Assert.assertEquals;

publicclassStudentAttendanceRecordITest {

privatestaticStudentAttendanceRecordItest;

privatestaticbooleanexpected;

privatestaticbooleanactual;

privatestaticStrings;

publicstaticvoidsetup(){

test =newStudentAttendanceRecordI();

}

publicvoidsetupForEachTest(){}

publicvoidtest1(){

s ="ALLAPPL";

expected =false;

actual =test.checkRecord(s);

assertEquals(expected,actual);

}

}