Update 1024.Video-Stitching.cpp

Greedy/1024.Video-Stitching/1024.Video-Stitching.cpp

@@ -1,40 +1,38 @@
 class Solution {
     static bool cmp(vector<int>&a, vector<int>&b)
     {
-        if (a[0]==b[0])
-            return a[1]>b[1];
-        else
+        if (a[0]!=b[0])
             return a[0]<b[0];
+        else
+            return a[1]>b[1];
     }
 public:
     int videoStitching(vector<vector<int>>& clips, int T) 
     {
-        sort(clips.begin(),clips.end(),cmp);
+        if (T==0) return 0;
+        sort(clips.begin(),clips.end(),cmp);        
 
-        if (clips[0][0]!=0) return -1;
-        int right = clips[0][1];
-        int idx = 0;
-        int count = 1;
-        if (clips[0][1]>=T) return count;
-
-        while (idx < clips.size())
-        {
-            int farReach = right;
-            while (idx<clips.size() && clips[idx][0]<=right)
+        int far = 0;
+        int i = 0;
+        int count = 0;
+
+        while (i < clips.size())
+        {            
+            int nextFar = far;
+            while (i<clips.size() && clips[i][0]<=far)
             {
-                farReach = max(farReach, clips[idx][1]);
-                idx++;
+                nextFar = max(nextFar, clips[i][1]);
+                i++;
             }
-            if (farReach == right)
-                return -1;
-
             count++;
-
-            if (farReach>=T) return count;
-            right = farReach;
-        }
-
-        return -1;
-
+
+            if (nextFar >= T)
+                return count;
+            else if (nextFar == far)
+                return -1;                            
+            far = nextFar;
+        }        
+
+        return -1;        
     }
 };