Create 1353. Maximum Number of Events That Can Be Attended (#835)

Author: Chayandas07

1353. Maximum Number of Events That Can Be Attended

@@ -0,0 +1,45 @@
+class DisjointSet {
+    vector<int> parent;
+public:
+    DisjointSet(int n) {
+        parent.resize(n);
+        for (int i = 0; i < n; i++) {
+            parent[i] = i;
+        }
+    }
+
+    int findUPar(int node) {
+        if (node == parent[node])
+            return node;
+        return parent[node] = findUPar(parent[node]);
+    }
+
+    void mark(int day){
+        parent[day]=day+1;
+    }
+};
+
+class Solution {
+public:
+    int maxEvents(vector<vector<int>>& events) {
+        vector<pair<int,int>> v;
+        int maxi=0;
+        for(int i=0;i<events.size();i++){
+            v.push_back({events[i][1],events[i][0]});
+            maxi=max(maxi,events[i][1]);
+        }
+        sort(v.begin(),v.end());
+        int cnt=0;
+        DisjointSet ds(maxi+2);
+        for(int i=0;i<v.size();i++){
+           int s=v[i].second;
+           int e=v[i].first;
+           int av=ds.findUPar(s);
+           if(av<=e){
+            cnt++;
+            ds.mark(av);
+           }
+        }
+        return cnt;
+    }
+};