friupdate14jan1

C++/BinarySearch.cpp

@@ -0,0 +1,34 @@
+/*
+
+Source: https://leetcode.com/problems/binary-search/
+
+Time: O(log base2 n), where n is the length of the given array(nums)
+Space: O(1), in-place
+
+*/
+
+class Solution {
+public:
+ int search(vector<int>& nums, int target) {
+
+ int start = 0;
+ int end = nums.size() - 1;
+
+ while(start <= end) {
+
+ int mid = start + ((end - start) >> 1);
+
+ if(nums[mid] == target) {
+ return mid;
+ }
+
+ if(nums[mid] < target) {
+ start = mid + 1;
+ } else {
+ end = mid - 1;
+ }
+ }
+
+ return -1;
+ }
+};

Java/AddBinary.java

@@ -2,8 +2,8 @@
 
 Source: https://leetcode.com/problems/add-binary/
 
-Time Comlexity : O(Max(m, n)), where m and n are the length of given Strings a and b respectively.
-Space Complexity : O(Max(m, n)), as we need a StringBuilder whose size is equal to max of length of 2 input strings
+Time Comlexity : O(max(m, n)), where m and n are the lengths of given Strings a and b respectively.
+Space Complexity : O(max(m, n)), as we need a StringBuilder whose size is equal to max of length of 2 input strings
 
 */
 
@@ -12,27 +12,29 @@ public String addBinary(String a, String b) {
 
  int aLen = a.length() - 1;
  int bLen = b.length() - 1;
- StringBuilder res = new StringBuilder(Math.max(aLen, bLen) + 2);
+ int maxLen = Math.max(aLen, bLen) + 2;
+ char[] res = new char[maxLen];
  int sum = 0;
 
  while(aLen >= 0 || bLen >= 0) {
 
- if(aLen >= 0 && a.charAt(aLen--) == '1') {
+ if(aLen >= 0 && a.charAt(aLen--)  == '1') {
  sum += 1;
  }
 
  if(bLen >= 0 && b.charAt(bLen--) == '1') {
  sum += 1;
  }
 
- res.append(sum & 1);
+ res[--maxLen] = (char)((sum & 1) + 48);
  sum >>= 1;
  }
 
  if(sum != 0) {
- res.append(1);
+ res[0] = '1';
+ return String.valueOf(res);
  }
 
- return res.reverse().toString();
+ return String.valueOf(res, 1, res.length - 1);
  }
 }

Java/BinarySearch.java

@@ -0,0 +1,33 @@
+/*
+
+Source: https://leetcode.com/problems/binary-search/
+
+Time: O(log base2 n), where n is the length of the given array(nums)
+Space: O(1), in-place
+
+*/
+
+class Solution {
+ public int search(int[] nums, int target) {
+
+ int start = 0;
+ int end = nums.length - 1;
+
+ while(start <= end) {
+
+ int mid = start + (end - start ) >> 1;
+
+ if(nums[mid] == target) {
+ return mid;
+ }
+
+ if(nums[mid] < target) {
+ start = mid + 1;
+ } else {
+ end = mid - 1;
+ }
+ }
+
+ return -1;
+ }
+}