public List<Integer> findSubstring(String s, String[] words) {
List<Integer> res = new ArrayList<Integer>();
int wlength = words.length;
if (wlength == 0) return res;
int size = words[0].length();
int slength = s.length();
if (wlength * size > slength) return res;
HashMap<String, Integer> wordHashMap = new HashMap<String, Integer>();
for (int i = 0; i < wlength; i++)
wordHashMap.put(
words[i], !wordHashMap.containsKey(words[i]) ? 1 : wordHashMap.get(words[i]) + 1);
for (int i = 0; i < slength - size * wlength + 1; i++) {
HashMap<String, Integer> tempHashMap = new HashMap<String, Integer>(wordHashMap);
for (int j = 0; j < wlength; j++) {
String subString = s.substring(i + j * size, i + (j + 1) * size);
if (tempHashMap.containsKey(subString)) {
int count = tempHashMap.get(subString);
if (count == 1) tempHashMap.remove(subString);
else tempHashMap.replace(subString, count - 1);
} else {
break;
}
}
if (tempHashMap.isEmpty()) res.add(i);
}
return res;
}
public int longestConsecutive(int[] num) {
if (null == num || 0 == num.length) return 0;
int max = 1;
HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();
for (int i : num) {
if (map.containsKey(i)) continue;
map.put(i, 1);
if (map.containsKey(i - 1)) max = Math.max(max, merge(map, i - 1, i));
if (map.containsKey(i + 1)) max = Math.max(max, merge(map, i, i + 1));
}
return max;
}
public String minWindow(String s, String t) {
if (s.length() == 0 || t.length() > s.length()) return "";
HashMap<Character, Integer> target = new HashMap<Character, Integer>();
char[] tArr = t.toCharArray();
for (char one : tArr) {
if (!target.containsKey(one)) target.put(one, 1);
else target.put(one, target.get(one) + 1);
}
int len = s.length() + 1;
String res = "";
int pos = 0;
int prev = 0;
int count = 0;
HashMap<Character, Integer> m = new HashMap<Character, Integer>();
while (pos < s.length()) {
char oneChar = s.charAt(pos);
if (target.containsKey(oneChar)) {
if (!m.containsKey(oneChar)) {
count++;
m.put(oneChar, 1);
} else {
m.put(oneChar, m.get(oneChar) + 1);
if (m.get(oneChar) <= target.get(oneChar)) count++;
}
}
// move the prev to update len
if (count == t.length()) {
while (prev <= pos) {
char temp = s.charAt(prev);
if (!m.containsKey(temp)) prev++;
else if (m.get(temp) > target.get(temp)) {
prev++;
m.put(temp, m.get(temp) - 1);
} else {
if (pos - prev + 1 < len) {
len = pos - prev + 1;
res = s.substring(prev, pos + 1);
}
break;
}
}
}
pos++;
}
return res;
}
public boolean canPermutePalindrome(String s) {
// Time: O(n), Space: O(n)
if (s == null || s.length() == 0) {
return true;
}
HashMap<Character, Integer> map = new HashMap<Character, Integer>();
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (!map.containsKey(c)) {
map.put(c, 1);
} else {
map.put(c, map.get(c) + 1);
}
}
boolean single = false;
for (Integer i : map.values()) {
if (i % 2 == 1) {
if (single) {
return false;
}
single = true;
}
}
return true;
}
public int[] twoSum_hashmap(int[] numbers, int target) {
if (numbers == null || numbers.length < 2) {
return null;
}
HashMap<Integer, Integer> hs = new HashMap<Integer, Integer>();
for (int i = 0; i < numbers.length; i++) {
hs.put(numbers[i], i + 1);
}
int[] a = new int[2];
for (int i = 0; i < numbers.length; i++) {
if (hs.containsKey(target - numbers[i])) { // the complexity for containsKey is basically O(1)
int index1 = i + 1;
int index2 = hs.get(target - numbers[i]);
if (index1 == index2) {
continue;
}
a[0] = index1;
a[1] = index2;
return a;
}
}
return a;
}
/**
* @param k: The number k.
* @return: The kth prime number as description.
*/
public long kthPrimeNumber(int k) {
PriorityQueue<Long> queue = new PriorityQueue<Long>();
HashMap<Long, Boolean> map = new HashMap<Long, Boolean>();
Long[] Primes = new Long[3];
Primes[0] = Long.valueOf(3);
Primes[1] = Long.valueOf(5);
Primes[2] = Long.valueOf(7);
for (int i = 0; i < Primes.length; ++i) {
queue.add(Primes[i]);
map.put(Primes[i], true);
}
Long number = Primes[0];
for (int i = 1; i <= k; ++i) {
number = queue.poll();
for (int j = 0; j < Primes.length; ++j) {
if (map.containsKey(number * Primes[j])) {
continue;
} else {
map.put(number * Primes[j], true);
queue.add(number * Primes[j]);
}
}
}
return number;
}
/**
* @param nums1 an integer array
* @param nums2 an integer array
* @return an integer array
*/
public int[] intersection(int[] nums1, int[] nums2) {
// Write your code here
if (nums1 == null || nums2 == null) return null;
HashMap<Integer, Integer> map = new HashMap();
for (int i = 0; i < nums1.length; i++) {
if (map.get(nums1[i]) != null) {
map.put(nums1[i], map.get(nums1[i]) + 1);
} else {
map.put(nums1[i], 1);
}
}
ArrayList<Integer> list = new ArrayList();
for (int j = 0; j < nums2.length; j++) {
if (map.containsKey(nums2[j]) && map.get(nums2[j]) > 0) {
list.add(nums2[j]);
map.put(nums2[j], map.get(nums2[j]) - 1);
}
}
int[] result = new int[list.size()];
for (int k = 0; k < list.size(); k++) {
result[k] = list.get(k);
}
return result;
}
public List<List<Integer>> threeSum(int[] nums) {
List<List<Integer>> res = new ArrayList<List<Integer>>();
List<Integer> list = new ArrayList<Integer>();
HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();
quickSort(nums, 0, nums.length - 1);
for (int i = 0; i < nums.length; i++) {
if (i > 0 && nums[i] == nums[i - 1]) continue;
int target = 0 - nums[i];
for (int j = i + 1; j < nums.length; j++) {
int diff = target - nums[j];
if (map.containsKey(diff)) {
list.add(nums[i]);
list.add(diff);
list.add(nums[j]);
res.add(list);
list = new ArrayList<Integer>();
}
map.put(nums[j], j);
}
map.clear();
}
return res;
}
// @return an integer
public int get(int key) {
// write your code here
if (!hash.containsKey(key)) return -1;
ListNode cur = hash.get(key);
delete(cur);
add(cur);
return cur.val;
}
public boolean containsNearbyDuplicate(int[] nums, int k) {
HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();
for (int i = 0; i < nums.length; i++) {
if (map.containsKey(nums[i])) {
int preIndex = map.get(nums[i]);
if (i - preIndex <= k) return true;
}
map.put(nums[i], i);
}
return false;
}
/**
* Stores a bitmap for use by a game tile in a level.
*
* @param int resourceId - The bitmap resource ID.
* @return Bitmap - The Bitmap instance for the given resource ID.
*/
private Bitmap setAndGetGameTileBitmap(int resourceId) {
if (!mGameTileBitmaps.containsKey(resourceId)) {
BitmapFactory.Options opts = new BitmapFactory.Options();
opts.inJustDecodeBounds = true;
Bitmap bitmap = BitmapFactory.decodeResource(mGameContext.getResources(), resourceId);
if (bitmap != null) {
mGameTileBitmaps.put(resourceId, bitmap);
}
}
return mGameTileBitmaps.get(resourceId);
}
public int lengthOfLongestSubstring(String s) {
if (s.length() == 0) return 0;
HashMap<Character, Integer> map = new HashMap<>();
int max = 0;
for (int i = 0, j = 0; i < s.length(); i++) {
if (map.containsKey(s.charAt(i))) {
j = Math.max(j, map.get(s.charAt(i)) + 1);
}
map.put(s.charAt(i), i);
max = Math.max(max, i - j + 1);
}
return max;
}
public int singleNumber_On(int[] A) {
HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();
int i;
for (i = 0; i < A.length; i++) {
map.put(A[i], map.containsKey(A[i]) ? map.get(A[i]) + 1 : 1);
}
for (i = 0; i < A.length; i++) {
if (map.get(A[i]) != 3) {
break;
}
}
return A[i];
}
public boolean check(String s1, String s2) {
if (s1.equals(s2)) return true;
if (s1.length() == 1) return false;
HashMap<Character, Integer> map = new HashMap<Character, Integer>();
for (int i = 0; i < s1.length(); i++) {
char c = s1.charAt(i);
if (map.containsKey(c)) map.put(c, map.get(c) + 1);
else map.put(c, 1);
}
for (int i = 0; i < s2.length(); i++) {
char c = s2.charAt(i);
if (map.containsKey(c)) map.put(c, map.get(c) - 1);
else return false;
}
for (Map.Entry<Character, Integer> entry : map.entrySet()) {
int val = entry.getValue().intValue();
if (val != 0) return false;
}
for (int i = 1; i < s1.length(); i++) {
String left_s1 = s1.substring(0, i);
String right_s1 = s1.substring(i);
String left_s2 = s2.substring(0, i);
String right_s2 = s2.substring(i);
if (check(left_s1, left_s2) && check(right_s1, right_s2)) return true;
}
for (int i = 1; i < s1.length(); i++) {
String left_s1 = s1.substring(0, i);
String right_s1 = s1.substring(i);
String left_s2 = s2.substring(0, s1.length() - i);
String right_s2 = s2.substring(s1.length() - i);
if (check(left_s1, right_s2) && check(right_s1, left_s2)) return true;
}
return false;
}
public int[] intersect(int[] nums1, int[] nums2) {
HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();
List<Integer> intersect = new ArrayList<>();
for (int i : nums1) {
if (!map.containsKey(i)) {
map.put(i, 1);
} else {
map.put(i, map.get(i) + 1);
}
}
for (int i : nums2) {
if (map.containsKey(i) && map.get(i) > 0) {
intersect.add(i);
map.put(i, map.get(i) - 1);
}
}
int[] result = new int[intersect.size()];
int i = 0;
for (Integer num : intersect) {
result[i++] = num;
}
return result;
}
public boolean isIsomorphic(String s, String t) {
HashMap<Character, Character> map = new HashMap<>();
for (int i = 0; i < s.length(); i++) {
if (map.containsKey(s.charAt(i))) {
if (t.charAt(i) == map.get(s.charAt(i))) continue;
else {
return false;
}
} else if (map.containsValue(t.charAt(i))) {
return false;
}
map.put(s.charAt(i), t.charAt(i));
}
return true;
}
public boolean containsNearbyDuplicate(int[] nums, int k) {
HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();
int min = Integer.MAX_VALUE;
for (int i = 0; i < nums.length; i++) {
if (map.containsKey(nums[i])) {
int preIndex = map.get(nums[i]);
int gap = i - preIndex;
min = Math.min(min, gap);
}
map.put(nums[i], i);
}
if (min <= k) {
return true;
} else {
return false;
}
}
// @param key, an integer
// @param value, an integer
// @return nothing
public void set(int key, int value) {
// write your code here
if (hash.containsKey(key)) {
hash.get(key).val = value;
get(key);
} else {
ListNode cur = new ListNode(key, value);
if (len == capacity) {
ListNode temp = head.next;
delete(temp);
hash.remove(temp.key);
hash.put(key, cur);
add(cur);
} else {
add(cur);
hash.put(key, cur);
len++;
}
}
}
public int maxPoints(Point[] points) {
if (points == null || points.length == 0) {
return 0;
}
HashMap<Double, Integer> map = new HashMap<>();
int res = 0;
for (int i = 0; i < points.length; i++) {
int vertical = 0;
int dup = 1;
for (int j = i + 1; j < points.length; j++) {
if (points[i].x == points[j].x) {
if (points[i].y == points[j].y) {
dup++;
} else {
vertical++;
}
} else {
double slope;
if (points[j].y == points[i].y) {
slope = 0.0;
} else {
slope = (1.0) * (points[j].y - points[i].y) / (points[j].x - points[i].x);
}
if (!map.containsKey(slope)) {
map.put(slope, 1);
} else {
map.put(slope, map.get(slope) + 1);
}
}
}
for (Integer val : map.values()) {
res = Math.max(res, dup + val);
}
res = Math.max(res, dup + vertical);
map.clear();
}
return res;
}
/*
我们有一个O(N)的解法。使用Map 来记录index, sum的值。当遇到两个index的sum相同时，表示从index1+1到index2是一个解。
注意：添加一个index = -1作为虚拟节点。这样我们才可以记录index1 = 0的解。
空间复杂度：O(N)
*/
public ArrayList<Integer> subarraySum(int[] nums) {
ArrayList<Integer> rst = new ArrayList<Integer>();
if (nums == null || nums.length == 0) {
return rst;
}
int sum = 0;
HashMap<Integer, Integer> map = new HashMap<Integer, Integer>(); // key: sum, value: index
map.put(0, -1);
// we know that sub-array (a,b) has zero sum if SUM(0 ... a-1) = SUM(0 ... b)
for (int i = 0; i < nums.length; i++) {
sum += nums[i];
if (map.containsKey(sum)) {
// For example:
// -3 1 2 -3 4
// SUM: 0 -3 -2 0 -3 1
// then we got the solution is : 0 - 2
rst.add(map.get(sum) + 1);
rst.add(i);
return rst;
}
map.put(sum, i);
} // for
return rst;
}
public List<Integer> findSubstring(String s, String[] words) {
// alg:
// extra HashMap to count remaining word in words.
// use two pointers to create a sliding window of length == len(word) in words.
// check in HashMap if words element is found, and update the counter
// if a word in current sliding window is not in HashMap.keys, or if a counter is < 0,
// HashMap back to the original and window moves a step a head.
// corner case:
// null, empty, s shorter then the total length of words
if (s == null || words == null) {
return null;
}
int sl = s.length();
int wn = words.length;
if (sl == 0 || wn == 0) {
return null;
}
int wl = words[0].length();
if (sl < wn * wl) {
return null;
}
// general case:
List<Integer> rst = new ArrayList<Integer>();
HashMap<String, Integer> wCounter = new HashMap<String, Integer>();
for (String w : words) {
if (!wCounter.containsKey(w)) {
wCounter.put(w, 1);
} else {
wCounter.put(w, wCounter.get(w) + 1);
}
}
String[] sWords = new String[sl - wn * wl];
for (int i = 0; i < sWords.length; i++) {
sWords[i] = s.substring(i, i + wl * wn);
}
HashMap<String, Integer> swCounter;
int index;
String curr;
for (int j = 0; j < sWords.length; j++) {
swCounter = new HashMap<String, Integer>();
index = 0;
while (index < wn * wl) {
curr = sWords[j].substring(index, index + wl);
if (!swCounter.containsKey(curr)) {
swCounter.put(curr, 1);
} else {
swCounter.put(curr, swCounter.get(curr) + 1);
}
index += wl;
}
if (swCounter.equals(wCounter)) {
rst.add(j);
}
}
return rst;
}
boolean contains(int child) {
return rec.containsKey(child);
}
public List<Integer> findSubstring(String s, String[] words) {
// alg:
// extra HashMap to count remaining word in words.
// use two pointers to create a sliding window of length == len(word) in words.
// check in HashMap if words element is found, and update the counter
// if a word in current sliding window is not in HashMap.keys, or if a counter is < 0,
// HashMap back to the original and window moves a step a head.
// corner case:
// null, empty, s shorter then the total length of words
if (s == null || words == null) {
return null;
}
int sl = s.length();
int wn = words.length;
if (sl == 0 || wn == 0) {
return null;
}
int wl = words[0].length();
if (sl < wn * wl) {
return null;
}
// general case:
HashMap<String, int[]> counter = new HashMap<String, int[]>();
for (String w : words) {
if (!counter.containsKey(w)) {
counter.put(
w,
new int[] {
1, 1
}); // second element in value array is the back up of original counter record to
// recover.
} else {
counter.get(w)[0] = counter.get(w)[0] + 1;
counter.get(w)[1] = counter.get(w)[0];
}
}
int p1 = 0;
int p2 = p1 + wl - 1; // sliding window.
int remain = wn; // remain words to find in words
List<Integer> rst = new ArrayList<Integer>();
int index = p1;
String curr = "";
while (p2 < sl) {
curr = s.substring(p1, p2 + 1);
if (counter.containsKey(curr) == false) {
for (int[] val : counter.values()) {
val[0] = val[1];
}
p1 = index + 1;
p2 = p1 + wl - 1;
remain = wn;
index = p1;
continue;
}
counter.get(curr)[0] = counter.get(curr)[0] - 1;
if (counter.get(curr)[0] < 0) {
for (int[] val : counter.values()) {
val[0] = val[1];
}
p1 = index + 1;
p2 = p1 + wl - 1;
remain = wn;
index = p1;
continue;
}
remain--;
p2 += wl;
p1 += wl;
if (remain == 0) {
rst.add(index);
for (int[] val : counter.values()) {
val[0] = val[1];
}
p1 = index + 1;
p2 = p1 + wl - 1;
remain = wn;
index = p1;
}
}
return rst;
}
/**
* Returns <tt>true</tt> if this set contains the specified element.
*
* @param o element whose presence in this set is to be tested.
* @return <tt>true</tt> if this set contains the specified element.
*/
public boolean contains(Object o) {
return map.containsKey(o);
}