From b1a2b7d1f6e6e569ccdfd3b14ff8d1cb959c6e83 Mon Sep 17 00:00:00 2001
From: wisdompeak <guan.huifeng@gmail.com>
Date: Wed, 23 Dec 2020 19:33:12 -0800
Subject: [PATCH] Update 1024.Video-Stitching.cpp

---
 .../1024.Video-Stitching.cpp                  | 50 +++++++++----------
 1 file changed, 24 insertions(+), 26 deletions(-)

diff --git a/Greedy/1024.Video-Stitching/1024.Video-Stitching.cpp b/Greedy/1024.Video-Stitching/1024.Video-Stitching.cpp
index 51ba28a6c..761ed1e1a 100644
--- a/Greedy/1024.Video-Stitching/1024.Video-Stitching.cpp
+++ b/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;        
     }
 };