Added codes for 21 Jan

GeeksForGeeks/21-1-24/GFG.java

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+//{ Driver Code Starts
+import java.io.*;
+import java.util.*;
+
+
+class IntMatrix
+{
+    public static int[][] input(BufferedReader br, int n, int m) throws IOException
+    {
+        int[][] mat = new int[n][];
+
+        for(int i = 0; i < n; i++)
+        {
+            String[] s = br.readLine().trim().split(" ");
+            mat[i] = new int[s.length];
+            for(int j = 0; j < s.length; j++)
+                mat[i][j] = Integer.parseInt(s[j]);
+        }
+
+        return mat;
+    }
+
+    public static void print(int[][] m)
+    {
+        for(var a : m)
+        {
+            for(int e : a)
+                System.out.print(e + " ");
+            System.out.println();
+        }
+    }
+
+    public static void print(ArrayList<ArrayList<Integer>> m)
+    {
+        for(var a : m)
+        {
+            for(int e : a)
+                System.out.print(e + " ");
+            System.out.println();
+        }
+    }
+}
+
+class GFG {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int t;
+        t = Integer.parseInt(br.readLine());
+        while(t-- > 0){
+
+            int n; 
+            n = Integer.parseInt(br.readLine());
+
+
+            int m; 
+            m = Integer.parseInt(br.readLine());
+
+
+            int[][] edges = IntMatrix.input(br, m, 2);
+
+            Solution obj = new Solution();
+            int res = obj.vertexCover(n, m, edges);
+
+            System.out.println(res);
+
+        }
+    }
+}
+
+// } Driver Code Ends
+
+
+class Solution 
+{
+    public static int vertexCover(int n, int m, int[][] edges) 
+    {
+        // code here
+        int ans = Integer.MAX_VALUE;
+
+        // The use of labels is especially handy when dealing with nested loops. 
+        // It allows you to specify which loop the continue or break statement should affect
+        // especially when there are multiple levels of nested loops.
+        outerloop:
+        for(int i = 0; i <= 1 << n; i++)
+        {
+            for(int j = 0; j < m; j++)
+            {
+                if(!((1 << (edges[j][0] - 1) & i) != 0
+                        || (1 << (edges[j][1] - 1) & i) != 0))
+                        {
+                            continue outerloop; // This continues outerloop and not innerloop
+                        }
+            }
+
+            ans = Math.min(ans, Integer.bitCount(i));
+        }
+
+        return ans;
+    }
+}

GeeksForGeeks/21-1-24/README.md

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+Time complexity - O(m * n^2)
+Space complexity - O(1)

LeetCode/21-1-24/README.md

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+Time complexity - O(n)
+Space complexity - O(1)

LeetCode/21-1-24/Solution.java

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+class Solution 
+{
+    // using dp, but not array
+
+    public int rob(int[] nums) 
+    {
+        int prev1 = 0; // dp[i - 1]
+        int prev2 = 0; // dp[i - 2]
+
+        for (int num : nums) 
+        {
+            int dp = Math.max(prev1, prev2 + num);
+            prev2 = prev1;
+            prev1 = dp;
+        }
+
+        return prev1;
+    }
+}