update

Author: xiaoyaoworm

218_getSkyline.java

@@ -0,0 +1,34 @@
+public class Solution {
+    public List<int[]> getSkyline(int[][] buildings) {
+        List<int[]> result = new ArrayList<int[]>();
+        List<int[]> height = new ArrayList<int[]>();
+        
+        for(int[] b: buildings){
+            height.add(new int[]{b[0], -b[2]});
+            height.add(new int[]{b[1], b[2]});
+        }
+        
+        Comparator<int[]> comparator = new Comparator<int[]>(){
+            public int compare(int[] a, int[] b){
+                if(a[0]!=b[0]) return a[0]-b[0];
+                else return a[1]-b[1];
+            }
+        };
+        
+        Collections.sort(height, comparator);
+        
+        PriorityQueue<Integer> pq = new PriorityQueue<Integer>(Collections.reverseOrder());
+        pq.offer(0);
+        int prev = 0;
+        for(int[] h: height){
+            if(h[1] < 0) pq.add(-h[1]);
+            else pq.remove(h[1]);
+            int cur = pq.peek();
+            if(prev != cur){
+                result.add(new int[]{h[0],cur});
+                prev = cur;
+            }
+        }
+        return result;
+    }
+}

393_validUtf8.java

@@ -3,7 +3,8 @@ public boolean validUtf8(int[] data) {
         //All & or | needs this ()!!!
         if(data == null || data.length == 0) return false;
         int numOfBytes = 0;
-        for(int i = 0; i < data.length; i++){
+        int i = 0;
+        while(i < data.length){
             if(data[i] > 255) return false; //256: 100000000(one 1 and eight 0)
             else if((data[i] & 128) == 0) numOfBytes = 1; //128: 10000000 (one 1 and seven 0) 
             else if((data[i] & 224) == 192) numOfBytes = 2; //224: 11100000, 192: 11000000
@@ -16,7 +17,7 @@ public boolean validUtf8(int[] data) {
                 if(i + j >= data.length) return false;
                 if((data[i+j] & 192) != 128) return false; //check whether it is 10XXXXXXX
             }
-            i = i+numOfBytes-1; //dont forget move i.
+            i = i+numOfBytes; //dont forget move i.
         }
         return true;