added FirstUniqueCharacterInAString.java

company/amazon/FirstUniqueCharacterInAString.java

@@ -0,0 +1,34 @@
+//Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1.
+//
+//Examples:
+//
+//s = "leetcode"
+//return 0.
+//
+//s = "loveleetcode",
+//return 2.
+//Note: You may assume the string contain only lowercase letters.
+
+class FirstUniqueCharacterInAString {
+    public int firstUniqChar(String s) {
+        HashMap<Character, Integer> characters = new HashMap<Character, Integer>();
+        for(int i = 0; i < s.length(); i++) {
+            char current = s.charAt(i);
+            if(characters.containsKey(current)) {
+                characters.put(current, -1);
+            } else {
+                characters.put(current, i);
+            }
+        }
+
+        int min = Integer.MAX_VALUE;
+        for(char c: characters.keySet()) {
+            if(characters.get(c) > -1 && characters.get(c) < min) {
+                min = characters.get(c);
+            }
+        }
+
+        return min == Integer.MAX_VALUE ? -1 : min;
+
+    }
+}

company/bloomberg/FirstUniqueCharacterInAString.java

@@ -0,0 +1,34 @@
+//Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1.
+//
+//Examples:
+//
+//s = "leetcode"
+//return 0.
+//
+//s = "loveleetcode",
+//return 2.
+//Note: You may assume the string contain only lowercase letters.
+
+class FirstUniqueCharacterInAString {
+    public int firstUniqChar(String s) {
+        HashMap<Character, Integer> characters = new HashMap<Character, Integer>();
+        for(int i = 0; i < s.length(); i++) {
+            char current = s.charAt(i);
+            if(characters.containsKey(current)) {
+                characters.put(current, -1);
+            } else {
+                characters.put(current, i);
+            }
+        }
+
+        int min = Integer.MAX_VALUE;
+        for(char c: characters.keySet()) {
+            if(characters.get(c) > -1 && characters.get(c) < min) {
+                min = characters.get(c);
+            }
+        }
+
+        return min == Integer.MAX_VALUE ? -1 : min;
+
+    }
+}

company/google/FirstUniqueCharacterInAString.java

@@ -0,0 +1,34 @@
+//Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1.
+//
+//Examples:
+//
+//s = "leetcode"
+//return 0.
+//
+//s = "loveleetcode",
+//return 2.
+//Note: You may assume the string contain only lowercase letters.
+
+class FirstUniqueCharacterInAString {
+    public int firstUniqChar(String s) {
+        HashMap<Character, Integer> characters = new HashMap<Character, Integer>();
+        for(int i = 0; i < s.length(); i++) {
+            char current = s.charAt(i);
+            if(characters.containsKey(current)) {
+                characters.put(current, -1);
+            } else {
+                characters.put(current, i);
+            }
+        }
+
+        int min = Integer.MAX_VALUE;
+        for(char c: characters.keySet()) {
+            if(characters.get(c) > -1 && characters.get(c) < min) {
+                min = characters.get(c);
+            }
+        }
+
+        return min == Integer.MAX_VALUE ? -1 : min;
+
+    }
+}

company/microsoft/FirstUniqueCharacterInAString.java

@@ -0,0 +1,34 @@
+//Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1.
+//
+//Examples:
+//
+//s = "leetcode"
+//return 0.
+//
+//s = "loveleetcode",
+//return 2.
+//Note: You may assume the string contain only lowercase letters.
+
+class FirstUniqueCharacterInAString {
+    public int firstUniqChar(String s) {
+        HashMap<Character, Integer> characters = new HashMap<Character, Integer>();
+        for(int i = 0; i < s.length(); i++) {
+            char current = s.charAt(i);
+            if(characters.containsKey(current)) {
+                characters.put(current, -1);
+            } else {
+                characters.put(current, i);
+            }
+        }
+
+        int min = Integer.MAX_VALUE;
+        for(char c: characters.keySet()) {
+            if(characters.get(c) > -1 && characters.get(c) < min) {
+                min = characters.get(c);
+            }
+        }
+
+        return min == Integer.MAX_VALUE ? -1 : min;
+
+    }
+}

leetcode/hash-table/FirstUniqueCharacterInAString.java

@@ -0,0 +1,34 @@
+//Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1.
+//
+//Examples:
+//
+//s = "leetcode"
+//return 0.
+//
+//s = "loveleetcode",
+//return 2.
+//Note: You may assume the string contain only lowercase letters.
+
+class FirstUniqueCharacterInAString {
+    public int firstUniqChar(String s) {
+        HashMap<Character, Integer> characters = new HashMap<Character, Integer>();
+        for(int i = 0; i < s.length(); i++) {
+            char current = s.charAt(i);
+            if(characters.containsKey(current)) {
+                characters.put(current, -1);
+            } else {
+                characters.put(current, i);
+            }
+        }
+
+        int min = Integer.MAX_VALUE;
+        for(char c: characters.keySet()) {
+            if(characters.get(c) > -1 && characters.get(c) < min) {
+                min = characters.get(c);
+            }
+        }
+
+        return min == Integer.MAX_VALUE ? -1 : min;
+
+    }
+}

leetcode/string/FirstUniqueCharacterInAString.java

@@ -0,0 +1,34 @@
+//Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1.
+//
+//Examples:
+//
+//s = "leetcode"
+//return 0.
+//
+//s = "loveleetcode",
+//return 2.
+//Note: You may assume the string contain only lowercase letters.
+
+class FirstUniqueCharacterInAString {
+    public int firstUniqChar(String s) {
+        HashMap<Character, Integer> characters = new HashMap<Character, Integer>();
+        for(int i = 0; i < s.length(); i++) {
+            char current = s.charAt(i);
+            if(characters.containsKey(current)) {
+                characters.put(current, -1);
+            } else {
+                characters.put(current, i);
+            }
+        }
+
+        int min = Integer.MAX_VALUE;
+        for(char c: characters.keySet()) {
+            if(characters.get(c) > -1 && characters.get(c) < min) {
+                min = characters.get(c);
+            }
+        }
+
+        return min == Integer.MAX_VALUE ? -1 : min;
+
+    }
+}