3495 Minimum Operations To Make Array Elements Zero.cpp

3495 Minimum Operations To Make Array Elements Zero.cpp

@@ -0,0 +1,37 @@
+class Solution {
+public:
+    long long minOperations(vector<vector<int>>& queries) {
+        long long ans=0;
+        for(int i=0;i<queries.size();i++){
+            long long log4a=1;
+            long long a=queries[i][0];
+            long long b=queries[i][1];
+            long long log4b=1;
+            while(a>3){
+                log4a++;
+                a/=4;
+            }
+            while(b>3){
+                log4b++;
+                b/=4;
+            }
+            if(log4a==log4b){
+                ans+=((queries[i][1]-queries[i][0]+1)*log4a+1)/2;
+                continue;
+            }
+            long long st=pow(4,log4a);
+            long long end=pow(4,(log4b-1));
+            long long sum=(st-queries[i][0])*log4a;
+            sum+=(queries[i][1]-end+1)*log4b;
+            log4a++;
+            while(log4a<log4b){
+                long long temp=st*4;
+                sum+=(temp-st)*log4a;
+                st=temp;
+                log4a++;
+            }
+            ans+=(sum+1)/2;
+        }
+        return ans;
+    }
+};

3619_Count_Islands__with_Total_Value_Divisible_By_K.cpp

@@ -0,0 +1,52 @@
+class Solution {
+public:
+    int countIslands(vector<vector<int>>& grid, int k) {
+        int m=grid.size();
+        int n=grid[0].size();
+        int cnt=0;
+        vector<vector<bool>> visited(m,vector<bool> (n));
+        for(int i=0;i<m;i++){
+            for(int j=0;j<n;j++){
+                //cout<<i<<" "<<j<<" "<<visited[i][j]<<'\n';
+                if(!(visited[i][j])&&grid[i][j]>0){
+                    long long sum=0;
+                    int a=i;
+                    int b=j;
+                    dfs(grid,visited,a,b,sum,m,n);
+                    //cout<<sum<<" "<<grid[i][j]<<" "<<i<<" "<<j<<"\n";
+                    if(sum%k==0){
+                        cnt++;
+                    }
+                }
+            }
+        }
+        return cnt;
+    }
+    void dfs(vector<vector<int>>& grid, vector<vector<bool>> &visited, int &x,int &y, long long &sum, int m, int n){
+        sum+=grid[x][y];
+        //cout<<grid[x][y]<<" "<<x<<" "<<y<<" ";
+        visited[x][y]=true;
+        if(x<m-1){
+           int l=x+1;
+           if(grid[l][y]!=0&&!visited[l][y])
+            dfs(grid,visited,l,y,sum,m,n);
+        }
+        if(y<n-1){
+            int h=y+1;
+            if(grid[x][h]!=0&&!visited[x][h])
+            dfs(grid,visited,x,h,sum,m,n);
+        }
+        if(x>0){
+            int a=x-1;
+            if(grid[a][y]>0 &&!visited[a][y])
+             dfs(grid,visited,a,y,sum,m,n);
+        }
+        if(y>0){
+            int b=y-1;
+            if(grid[x][b]>0 &&!visited[x][b])
+            dfs(grid,visited,x,b,sum,m,n);
+        }
+
+    }
+
+};