fd

Author: dingjikerbo

leetcode/solution/src/ReverseWordsInAString.java

@@ -1,48 +1,34 @@
 public class ReverseWordsInAString {
 
-
-    // 耗时10ms
-    public String reverseWords(String s) {
-        StringBuilder sb = new StringBuilder();
-
-        boolean inWord = false;
-        char[] cc = s.toCharArray();
-        for (int i = cc.length - 1, idx = 0; i >= 0; i--) {
-            if (cc[i] != ' ') {
-                if (!inWord && sb.length() > 0) {
-                    sb.append(' ');
-                }
-                inWord = true;
-                sb.insert(idx, cc[i]);
-            } else if (inWord) {
-                idx = sb.length() + 1;
-                inWord = false;
-            }
+    public static String reverseWords(String s) {
+        s = s.trim();
+        if (s.length() == 0) {
+            return "";
         }
-
-        return sb.toString();
-    }
-
-    // 耗时18ms
-    public String reverseWords2(String s) {
         StringBuilder sb = new StringBuilder();
-
-        for (int i = 0, j = 0; i < s.length(); ) {
+        boolean flag = false;
+        int i = s.length() - 1, j = i;
+        for (i = s.length() - 1, j = i; i >= 0; i--) {
             if (s.charAt(i) == ' ') {
-                i++;
-                j = i;
-            } else if (j >= s.length() || s.charAt(j) == ' ') {
-                sb.insert(0, s.substring(i, j) + " ");
-                i = j;
+                if (!flag) {
+                    continue;
+                } else {
+                    sb.append(s.substring(i + 1, j + 1)).append(" ");
+                    flag = false;
+                }
             } else {
-                j++;
+                if (!flag) {
+                    j = i;
+                    flag = true;
+                }
             }
         }
-
-        if (sb.length() > 0) {
+        if (j > i) {
+            sb.append(s.substring(i + 1, j + 1));
+        }
+        if (sb.charAt(sb.length() - 1) == ' ') {
             sb.setLength(sb.length() - 1);
         }
-
         return sb.toString();
     }
 }

leetcode/src/Main.java

@@ -2,40 +2,38 @@
 
 public class Main {
 
-    public static int myAtoi(String str) {
-        int i = 0, sign = 1;
-        for ( ; i < str.length() && str.charAt(i) == ' '; i++);
-        if (i < str.length()) {
-            char csign = str.charAt(i);
-            if (csign == '-') {
-                sign = -1;
-                i++;
-            } else if (csign == '+') {
-                sign = 1;
-                i++;
-            } else if (csign < '0' || csign > '9') {
-                return 0;
-            } else {}
-        }
-        long number = 0;
-        for ( ; i < str.length(); i++) {
-            char c = str.charAt(i);
-            if (c < '0' || c > '9') {
-                break;
-            }
-            number = number * 10 + (c - '0');
+    public static String reverseWords(String s) {
+        int i, j = 0;
+        boolean flag = false;
 
-            if (number * sign > Integer.MAX_VALUE) {
-                return Integer.MAX_VALUE;
-            }
-            if (number * sign < Integer.MIN_VALUE) {
-                return Integer.MIN_VALUE;
+        StringBuilder sb = new StringBuilder();
+
+        for (i = s.length() - 1; i >= 0; i--) {
+            if (s.charAt(i) == ' ') {
+                if (!flag) {
+                    continue;
+                } else {
+                    flag = false;
+                    sb.append(s.substring(i + 1, j + 1)).append(" ");
+                }
+            } else {
+                if (!flag) {
+                    flag = true;
+                    j = i;
+                }
             }
         }
-        return (int) (number * sign);
+
+        if (flag) {
+            sb.append(s.substring(i + 1, j + 1));
+        }
+        if (sb.length() > 0 && sb.charAt(sb.length() - 1) == ' ') {
+            sb.setLength(sb.length() - 1);
+        }
+        return sb.toString();
     }
 
     public static void main(String[] args) {
-        System.out.println(myAtoi("-42"));
+        System.out.println(reverseWords("the sky is blue"));
     }
 }