From 3ca1f9926a23bc0a7a248e2e05f9a06993d691f7 Mon Sep 17 00:00:00 2001
From: Aadil <77232799+aadil42@users.noreply.github.com>
Date: Thu, 22 Jun 2023 19:04:37 +0530
Subject: [PATCH 1/5] Create 1898-maximum-number-of-removable-characters.js

Solved maximum-number-of-removable-characters in JS.
---
 ...-maximum-number-of-removable-characters.js | 89 +++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 javascript/1898-maximum-number-of-removable-characters.js

diff --git a/javascript/1898-maximum-number-of-removable-characters.js b/javascript/1898-maximum-number-of-removable-characters.js
new file mode 100644
index 000000000..23185c6b3
--- /dev/null
+++ b/javascript/1898-maximum-number-of-removable-characters.js
@@ -0,0 +1,89 @@
+/**
+ * https://leetcode.com/problems/maximum-number-of-removable-characters/
+ * 
+ * Brute force
+ * Time O(removable.length * s.length) | Space O(1)
+ * @param {string} s
+ * @param {string} p
+ * @param {number[]} removable
+ * @return {number}
+ */
+var maximumRemovals1 = function(s, p, removable) {
+
+    let k = 0;
+    // removable.reverse();
+    s = s.split('');
+    p = p.split('');
+    for(let i = 0; i < removable.length; i++) {
+        s[removable[i]] = -1;
+        if(isSubSet()) {
+            k++;
+        } else {
+            return k;
+        }
+    }
+
+  function isSubSet() {
+      let i = 0;
+      let j = 0;
+
+      while(i < s.length && j < p.length) {
+          if(s[i] === p[j]) {
+              i++;
+              j++;
+          } else {
+              i++;
+          }
+      }
+      return j === p.length
+  }
+
+  return k;  
+};
+
+
+/**
+ * 
+ * Binary Search 
+ * n = length of string, k = length of removable
+ * Time O(log(k)*n) | Space O(k)
+ * @param {string} s
+ * @param {string} p
+ * @param {number[]} removable
+ * @return {number}
+ */
+var maximumRemovals = function(s, p, removable) {
+
+    s = s.split('');
+    p = p.split('');
+    let left = 0;
+    let right = removable.length - 1;
+    let k = 0;
+    while(left <= right) {
+        const mid = Math.floor((left+right)/2);
+        const hash = new Set(removable.slice(0, mid + 1));
+        if(isSubSet(hash))  {
+            k = Math.max(k, mid + 1);
+            left = mid + 1;
+        } else {
+            right = mid - 1;
+        }
+    }
+
+  function isSubSet(hash) {
+      let i = 0;
+      let j = 0;
+
+      while(i < s.length && j < p.length) {
+          if(s[i] === p[j] && !hash.has(i)) {
+              i++;
+              j++;
+          } else {
+              i++;
+          }
+      }
+      return j === p.length
+  }
+
+  return k;  
+};

From 6bafb1f104186b524e6d92eadf6b6f3def6c0e43 Mon Sep 17 00:00:00 2001
From: Aadil <77232799+aadil42@users.noreply.github.com>
Date: Tue, 4 Jul 2023 20:59:44 +0530
Subject: [PATCH 2/5] Update 1898-maximum-number-of-removable-characters.js

Avoiding else case and defining function outside the main solution function.
---
 ...-maximum-number-of-removable-characters.js | 113 ++++++++++--------
 1 file changed, 60 insertions(+), 53 deletions(-)

diff --git a/javascript/1898-maximum-number-of-removable-characters.js b/javascript/1898-maximum-number-of-removable-characters.js
index 23185c6b3..fdce8cf21 100644
--- a/javascript/1898-maximum-number-of-removable-characters.js
+++ b/javascript/1898-maximum-number-of-removable-characters.js
@@ -9,37 +9,39 @@
  * @return {number}
  */
 var maximumRemovals1 = function(s, p, removable) {
+  let k = 0;
+  // removable.reverse();
+  s = s.split('');
+  p = p.split('');
 
-    let k = 0;
-    // removable.reverse();
-    s = s.split('');
-    p = p.split('');
-    for(let i = 0; i < removable.length; i++) {
-        s[removable[i]] = -1;
-        if(isSubSet()) {
-            k++;
-        } else {
-            return k;
-        }
+  for (let i = 0; i < removable.length; i++) {
+    s[removable[i]] = -1;
+    if (isSubSet1(s, p)) {
+      k++;
+    } else {
+      return k;
     }
+  }
+
+  return k;
+};
 
-  function isSubSet() {
-      let i = 0;
-      let j = 0;
+// helper function.
+function isSubSet1(s, p) {
+  let i = 0;
+  let j = 0;
 
-      while(i < s.length && j < p.length) {
-          if(s[i] === p[j]) {
-              i++;
-              j++;
-          } else {
-              i++;
-          }
-      }
-      return j === p.length
+  while (i < s.length && j < p.length) {
+    if (s[i] === p[j]) {
+      i++;
+      j++;
+    } else {
+      i++;
+    }
   }
 
-  return k;  
-};
+  return j === p.length;
+}
 
 
 /**
@@ -53,37 +55,42 @@ var maximumRemovals1 = function(s, p, removable) {
  * @return {number}
  */
 var maximumRemovals = function(s, p, removable) {
+  s = s.split('');
+  p = p.split('');
+  let left = 0;
+  let right = removable.length - 1;
+  let k = 0;
 
-    s = s.split('');
-    p = p.split('');
-    let left = 0;
-    let right = removable.length - 1;
-    let k = 0;
-    while(left <= right) {
-        const mid = Math.floor((left+right)/2);
-        const hash = new Set(removable.slice(0, mid + 1));
-        if(isSubSet(hash))  {
-            k = Math.max(k, mid + 1);
-            left = mid + 1;
-        } else {
-            right = mid - 1;
-        }
-    }
+  while (left <= right) {
+    const mid = Math.floor((left + right) / 2);
+    const hash = new Set(removable.slice(0, mid + 1));
 
-  function isSubSet(hash) {
-      let i = 0;
-      let j = 0;
+    if (isSubSet(hash, s, p)) {
+      k = Math.max(k, mid + 1);
+      left = mid + 1;
+      continue;
+    }
 
-      while(i < s.length && j < p.length) {
-          if(s[i] === p[j] && !hash.has(i)) {
-              i++;
-              j++;
-          } else {
-              i++;
-          }
-      }
-      return j === p.length
+    right = mid - 1;
   }
 
-  return k;  
+  return k;
 };
+
+// helper function.
+function isSubSet(hash, s, p) {
+  let i = 0;
+  let j = 0;
+
+  while (i < s.length && j < p.length) {
+    if (s[i] === p[j] && !hash.has(i)) {
+      i++;
+      j++;
+      continue;
+    }
+
+    i++;
+  }
+
+  return j === p.length;
+}

From 03154cadd072c506dd7ce5ad0acd95d2e6e87d02 Mon Sep 17 00:00:00 2001
From: Aadil <77232799+aadil42@users.noreply.github.com>
Date: Sat, 22 Jul 2023 15:44:43 +0530
Subject: [PATCH 3/5] Update 1898-maximum-number-of-removable-characters.js

Updating the space complexity for the brute force approach.
---
 javascript/1898-maximum-number-of-removable-characters.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/javascript/1898-maximum-number-of-removable-characters.js b/javascript/1898-maximum-number-of-removable-characters.js
index fdce8cf21..3d50591da 100644
--- a/javascript/1898-maximum-number-of-removable-characters.js
+++ b/javascript/1898-maximum-number-of-removable-characters.js
@@ -2,7 +2,7 @@
  * https://leetcode.com/problems/maximum-number-of-removable-characters/
  * 
  * Brute force
- * Time O(removable.length * s.length) | Space O(1)
+ * Time O(removable.length * s.length) | Space O(n)
  * @param {string} s
  * @param {string} p
  * @param {number[]} removable

From 6ae6bb121f92b4d824a5717a33d2b3bc75c88122 Mon Sep 17 00:00:00 2001
From: Aadil <77232799+aadil42@users.noreply.github.com>
Date: Sat, 22 Jul 2023 15:52:22 +0530
Subject: [PATCH 4/5] Update 1898-maximum-number-of-removable-characters.js

Avoiding else case.
---
 javascript/1898-maximum-number-of-removable-characters.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/javascript/1898-maximum-number-of-removable-characters.js b/javascript/1898-maximum-number-of-removable-characters.js
index 3d50591da..e33eaf6e5 100644
--- a/javascript/1898-maximum-number-of-removable-characters.js
+++ b/javascript/1898-maximum-number-of-removable-characters.js
@@ -18,9 +18,9 @@ var maximumRemovals1 = function(s, p, removable) {
     s[removable[i]] = -1;
     if (isSubSet1(s, p)) {
       k++;
-    } else {
-      return k;
-    }
+      continue;
+    } 
+    return k;
   }
 
   return k;

From f58bdb22960767cfd599c9791e993ccb9e8cb47d Mon Sep 17 00:00:00 2001
From: aadil42 <77232799+aadil42@users.noreply.github.com>
Date: Thu, 7 Sep 2023 12:40:53 +0530
Subject: [PATCH 5/5] Update 1898-maximum-number-of-removable-characters.js

Using bitwise operation to get the middle value. Not converting the strings to array to keep the time complexity O(1).
---
 javascript/1898-maximum-number-of-removable-characters.js | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/javascript/1898-maximum-number-of-removable-characters.js b/javascript/1898-maximum-number-of-removable-characters.js
index e33eaf6e5..3ae59a871 100644
--- a/javascript/1898-maximum-number-of-removable-characters.js
+++ b/javascript/1898-maximum-number-of-removable-characters.js
@@ -48,21 +48,20 @@ function isSubSet1(s, p) {
  * 
  * Binary Search 
  * n = length of string, k = length of removable
- * Time O(log(k)*n) | Space O(k)
+ * Time O(log(k)*n) | Space O(1)
  * @param {string} s
  * @param {string} p
  * @param {number[]} removable
  * @return {number}
  */
 var maximumRemovals = function(s, p, removable) {
-  s = s.split('');
-  p = p.split('');
+
   let left = 0;
   let right = removable.length - 1;
   let k = 0;
 
   while (left <= right) {
-    const mid = Math.floor((left + right) / 2);
+    const mid = (left + right) >> 1;
     const hash = new Set(removable.slice(0, mid + 1));
 
     if (isSubSet(hash, s, p)) {