fd

Author: dingjikerbo

doc/Attention.md

@@ -96,6 +96,6 @@ return -1;
 不能直接写return o1 > o2 ? 1 : -1；
 因为可能存在重复的数，在TreeMap中查找key时通过comparator等于0，上述写法导致永远找不到key。
 
-三十，StringBuilder的insert(0, c)不要频繁调用，不如append，最后reverse。
+三十，StringBuilder的insert(0, c)不要频繁调用，看源码要array copy，性能很差。不如append，最后reverse。
 
 三十一，List在allAll一个PriorityQueue时，是不会带顺序的，正确的做法是while(!queue.isEmpty()) {list.add(queue.poll());}

leetcode/solution/src/LicenseKeyFormatting.java

@@ -2,19 +2,16 @@
  * 将字符串s按长度k为一组，从右往左重排，组之间用"-"分隔，还要转成大写
  * 注意别在最前面多加一个"-"，即下面判断i != 0
  */
-
-
 public class LicenseKeyFormatting {
 
-    // 耗时22ms
+    // 耗时13ms
     public String licenseKeyFormatting(String S, int K) {
         StringBuilder sb = new StringBuilder();
 
         for (int i = S.length() - 1, j = 0; i >= 0; i--) {
             if (S.charAt(i) != '-') {
                 if (j % K == 0 && sb.length() > 0) {
                     sb.append("-");
-                    j = 0;
                 }
 
                 sb.append(Character.toUpperCase(S.charAt(i)));

leetcode/solution/src/MeetingRoomsII.java

@@ -5,7 +5,7 @@
 
 public class MeetingRoomsII {
 
-    // 耗时17ms，时间复杂度O(nlgn)
+    // 耗时7ms，时间复杂度O(nlgn)
     public int minMeetingRooms(Interval[] intervals) {
         Arrays.sort(intervals, new Comparator<Interval>() {
             @Override

leetcode/src/Main.java

@@ -2,55 +2,6 @@
 
 public class Main {
 
-    public String nextClosestTime(String time) {
-        int[] number = new int[4];
-
-        time = time.substring(0, 2) + time.substring(3);
-
-        for (int i = 0; i < time.length(); i++) {
-            number[i] = time.charAt(i) - '0';
-        }
-
-        Arrays.sort(number);
-
-        StringBuilder sb = new StringBuilder(time);
-
-        int i;
-        for (i = 3; i >= 0; i--) {
-            char c = time.charAt(i);
-            int k = nextNumber(number, c - '0');
-            if (k >= 0) {
-                sb.setCharAt(i, (char) (k + '0'));
-                if (isValid(sb)) {
-                    break;
-                }
-                sb.setCharAt(i, c);
-            }
-        }
-        for (i++; i < 4; i++) {
-            sb.setCharAt(i, (char) (number[0] + '0'));
-        }
-        sb.insert(2, ':');
-        return sb.toString();
-    }
-
-    private boolean isValid(StringBuilder sb) {
-        boolean flag1 = sb.charAt(0) < '2' || (sb.charAt(0) == '2' && sb.charAt(1) <= '3');
-        boolean flag2 = sb.charAt(2) < '5' || (sb.charAt(2) == '5' && sb.charAt(3) <= '9');
-        return flag1 && flag2;
-    }
-
-    private int nextNumber(int[] number, int n) {
-        for (int i = 0; i < number.length; i++) {
-            if (number[i] > n) {
-                return number[i];
-            }
-        }
-        return -1;
-    }
-
     public static void main(String[] args) {
-        String s = new NextClosestTime().nextClosestTime("13:55");
-        System.out.println(s);
     }
 }