Added 4 solutions

varunu28 · varunu28 · commit f2eddae36a68 · 2018-10-18T08:31:55.000-07:00
diff --git a/Medium/Compare Version Numbers.java b/Medium/Compare Version Numbers.java
@@ -1,17 +1,41 @@
 class Solution {
-    public int compareVersion(String A, String B) {
-        String[] arrA = A.split("\\.");
-        String[] arrB = B.split("\\.");
-        
-        int length = Math.max(arrA.length, arrB.length);
-        for (int i=0;i<length;i++) {
-            Long n1 = i<arrA.length ? Long.parseLong(arrA[i]) : 0;
-            Long n2 = i<arrB.length ? Long.parseLong(arrB[i]) : 0;
-            
-            int comp = n1.compareTo(n2);
-            if (comp != 0) return comp;
+    public static int compareVersion(String version1, String version2) {
+        String[] v1 = version1.split("\\.");
+        String[] v2 = version2.split("\\.");
+
+        int v1Start = 0;
+        int v2Start = 0;
+
+        while (v1Start < v1.length || v2Start < v2.length) {
+
+            if (v1Start < v1.length && v2Start < v2.length) {
+                if (Integer.parseInt(v1[v1Start]) < Integer.parseInt(v2[v2Start])) {
+                    return -1;
+                } else if (Integer.parseInt(v1[v1Start]) > Integer.parseInt(v2[v2Start])) {
+                    return 1;
+                }
+
+                v1Start++;
+                v2Start++;
+            }
+            else if (v1Start < v1.length && v2Start == v2.length) {
+                if (Integer.parseInt(v1[v1Start]) > 0) {
+                    return 1;
+                }
+                else {
+                    v1Start++;
+                }
+            }
+            else {
+                if (Integer.parseInt(v2[v2Start]) > 0) {
+                    return -1;
+                }
+                else {
+                    v2Start++;
+                }
+            }
         }
-        
+
         return 0;
     }
 }
diff --git a/Medium/Find and Replace in String.java b/Medium/Find and Replace in String.java
@@ -0,0 +1,24 @@
+class Solution {
+    public String findReplaceString(String S, int[] indexes, String[] sources, String[] targets) {
+        Map<Integer, String> sourceMap = new HashMap<>();
+        Map<Integer, String> targetMap = new HashMap<>();
+        
+        for (int i=0; i<indexes.length; i++) {
+            sourceMap.put(indexes[i], sources[i]);
+            targetMap.put(indexes[i], targets[i]);
+        }
+        
+        StringBuilder sb = new StringBuilder();
+        for (int i=0; i<S.length(); i++) {
+            if (sourceMap.containsKey(i) && S.substring(i).startsWith(sourceMap.get(i))) {
+                sb.append(targetMap.get(i));
+                i += sourceMap.get(i).length() - 1;
+            }
+            else {
+                sb.append(S.charAt(i));
+            }
+        }
+        
+        return sb.toString();
+    }
+}
diff --git a/Medium/Maximum Size Subarray Sum Equals k.java b/Medium/Maximum Size Subarray Sum Equals k.java
@@ -0,0 +1,23 @@
+class Solution {
+    public static int maxSubArrayLen(int[] nums, int k) {
+        Map<Integer, Integer> map = new HashMap<>();
+        int sum = 0;
+        int max = 0;
+
+        map.put(0, -1);
+
+        for (int i=0; i<nums.length; i++) {
+            sum += nums[i];
+            int diff = sum - k;
+            if (map.containsKey(diff)) {
+                max = Math.max(max, i - map.get(diff));
+            }
+            
+            if (!map.containsKey(sum)) {
+                    map.put(sum, i);
+            }
+        }
+
+        return max;
+    }
+}
diff --git a/Medium/Reverse Words in a String II.java b/Medium/Reverse Words in a String II.java
@@ -1,29 +1,27 @@
 class Solution {
     public static void reverseWords(char[] str) {
-        int end = str.length-1;
+        reverse(str, 0, str.length);
+
         int start = 0;
-        char[] ans = new char[str.length];
-        
-        while(end >= 0) {
-            while (end >= 0  && str[end] != ' ') {
-                end--;
+        for (int i=0; i<str.length; i++) {
+            if (str[i] == ' ') {
+                reverse(str, start, i);
+                start = i + 1;
             }
+        }
 
-            int len = str.length - end - 1;
-            int temp = end + 1;
-
-            while (start < len) {
-                ans[start++] = str[temp++];
-            }
+        reverse(str, start, str.length);
+    }
 
-            if (start < str.length) {
-                ans[start++] = ' ';
-                end--;
-            }
+    private static void reverse(char[] str, int start, int end) {
+        for (int i=0; i<(end - start)/2; i++) {
+            swap(str, start+i, end-i-1);
         }
+    }
 
-        for(int i=0; i<ans.length; i++) {
-            str[i] = ans[i];
-        }
+    private static void swap(char[] str, int i, int j) {
+        char temp = str[i];
+        str[i] = str[j];
+        str[j] = temp;
     }
 }
