Create 1288.Remove-Covered-Intervals_v1.cpp

Greedy/1288.Remove-Covered-Intervals/1288.Remove-Covered-Intervals_v1.cpp

@@ -0,0 +1,29 @@
+class Solution {
+    static bool cmp(pair<int,int>&a, pair<int,int>&b)
+    {
+        if (a.first!=b.first)
+            return a.first < b.first;
+        else
+            return a.second > b.second;
+    }
+public:
+    int removeCoveredIntervals(vector<vector<int>>& intervals) 
+    {
+        vector<pair<int,int>>p;
+        for (auto& interval: intervals)
+        {
+            p.push_back({interval[0],1});
+            p.push_back({interval[1],-1});
+        }
+        sort(p.begin(), p.end(), cmp);
+        int diff = 0;
+        int ret = 0;
+        for (auto x: p)
+        {
+            diff += x.second;
+            if (x.second==-1 && diff == 0)
+                ret++;
+        }
+        return ret;
+    }
+};