newProblems

Author: shashankch

src/arrays/intersection.java

@@ -36,20 +36,10 @@ public static void main(String[] args) {
                 }
 
             }
-            
-
-
 
         }
 
 
-
-
-
-
     }
 
-
-
-
 }

src/arrays/practiceProblems.java

@@ -0,0 +1,256 @@
+package arrays;
+
+public class practiceProblems {
+
+    public static void sumBoundariesdiagonal(int n) {
+
+        int arr[][]=new int[n][n];
+
+        for(int i=0;i<n;i++){
+
+            for(int j=0;j<n;j++){
+
+            //    arr[i][j]=sc.nextInt();
+
+            }
+        }
+
+        int sum=0;
+        for(int i=0;i<n;i++){
+
+            for(int j=0;j<n;j++){
+
+
+                if(i==0 || j==0 || i==n-1 || j==n-1 || i==j || (i+j)==n-1){
+
+                    sum+=arr[i][j];
+                }
+
+            }
+
+
+        }
+
+        System.out.print(sum);
+
+    }
+
+    // input - input 2D array
+    public static void wavePrint(int input[][]){
+
+        for(int j=0;j<input[0].length;j++){
+
+
+            if((j&1)>0){
+
+
+                for(int i=input.length-1;i>=0;i--){
+
+                    System.out.print(input[i][j]+" ");
+
+                }
+
+            }
+            else{
+
+                for(int i=0;i<input.length;i++){
+
+                    System.out.print(input[i][j]+" ");
+                }
+
+            }
+
+        }
+
+    }
+    public static void spiralPrint(int matrix[][]){
+
+        int r=matrix.length;
+        int c=matrix[0].length;
+
+        int sc=0,ec=c-1;
+        int sr=0,er=r-1;
+
+        while(sc<=ec && sr<=er){
+
+
+            // print from left to right
+            for(int j=sc;j<=ec;j++){
+
+                System.out.print(matrix[sr][j]+" ");
+            }
+
+            sr++;
+
+            // print top to bottom
+            for(int i=sr;i<=er;i++){
+
+                System.out.print(matrix[i][ec]+" ");
+
+            }
+
+            ec--;
+
+            // print from right to left
+            if(sr<=er){
+                for(int j=ec;j>=sc;j--){
+
+                    System.out.print(matrix[er][j]+" ");
+                }
+
+                er--;
+            }
+
+            if(sc<=ec){
+                // print from bottom to top..
+                for(int i=er;i>=sr;i--){
+
+                    System.out.print(matrix[i][sc]+" ");
+
+                }
+
+                sc++;
+            }
+        }
+
+    }
+
+   // Leader, if all the elements following it (i.e. present at its right) are less than or equal to A[i].
+   public static void leaders(int[] input) {
+       int n=input.length;
+       int max=input[n-1];
+       System.out.print(max+" ");
+       for(int i=n-2;i>=0;i--){
+
+
+           if(input[i]>=max){
+               System.out.print(input[i]+" ");
+               max=input[i];
+           }
+
+       }
+
+   }
+
+   public static String minLengthWord(String input){
+
+        int n=input.length();
+        int min=Integer.MAX_VALUE;
+        int start=0;
+        int pos=-1;
+        for(int i=0;i<n;i++){
+
+
+            if(input.charAt(i)==' ' || i==input.length()-1){
+
+
+                if(i==input.length()-1){
+
+
+                    int end=input.length()-1;
+                    int curlen=end-start+1;
+
+                    if(curlen<min){
+                        min=curlen;
+                        pos=start;
+                    }
+
+                }
+                else{
+
+                    int end=i-1;
+                    int curlen=end-start+1;
+
+                    if(curlen<min){
+                        min=curlen;
+                        pos=start;
+                    }
+
+                    start=i+1;
+
+                }
+
+
+
+            }
+
+
+
+        }
+
+        String ans="";
+        while(pos<n && input.charAt(pos)!=' ')
+        {
+
+            ans+=input.charAt(pos)+"";
+            pos++;
+
+
+        }
+
+
+        return ans;
+
+
+
+    }
+
+    //two sorted array increasing order find intersection path maxsum
+    public static long maximumSumPath(int[] input1, int[] input2) {
+
+        int n=input1.length;
+        int m=input2.length;
+
+        int i=0,j=0;
+        long one=0,two=0,sum=0;
+
+        while(i<n && j<m){
+
+
+            if(input1[i]<input2[j]){
+
+                one+=input1[i];
+                i++;
+            }
+
+            else if(input2[j]<input1[i]){
+
+                two+=input2[j];
+                j++;
+            }
+            else if(input1[i]==input2[j]){
+
+                one+=input1[i];
+                two+=input2[j];
+                i++;
+                j++;
+
+
+                sum+=Math.max(one,two);
+
+                one=0;
+                two=0;
+            }
+
+
+        }
+
+        while(i<n){
+
+            one+=input1[i];
+            i++;
+
+        }
+
+        while(j<m){
+
+            two+=input2[j];
+            j++;
+        }
+
+        sum+=Math.max(one,two);
+
+        return sum;
+
+    }
+}

src/arrays/starter.java

@@ -2,8 +2,6 @@
 
 public class starter {
 
-    public static void main(String[] args) {
-        System.out.println("hello world");
-    }
+
 
 }

src/backtracking/NQueen.java

@@ -0,0 +1,90 @@
+package backtracking;
+
+public class NQueen {
+
+
+    public static boolean issafe(int board[][],int i,int j,int n){
+
+        for(int row=0;row<i;row++){
+
+            if(board[row][j]==1){
+                return false;
+            }
+
+        }
+
+        int x=i;
+        int y=j;
+
+        while(x>=0 && y>=0){
+
+
+            if(board[x][y]==1){
+                return false;
+            }
+            x--;
+            y--;
+
+        }
+
+        x=i;
+        y=j;
+
+
+        while(x>=0 && y<=n){
+
+            if(board[x][y]==1){
+                return false;
+            }
+            x--;
+            y++;
+        }
+        return true;
+
+    }
+
+    public static boolean solve(int board[][],int i,int n){
+
+        if(i==n+1){
+
+            //  board[n][n]=1;
+            for(int p=0;p<=n;p++){
+
+                for(int q=0;q<=n;q++){
+
+                    System.out.print(board[p][q]+" ");
+                }
+            }
+
+            System.out.println();
+            return false;
+        }
+         for(int j=0;j<=n;j++){
+
+             if(issafe(board,i,j,n)){
+
+                board[i][j]=1;
+                boolean result=solve(board,i+1,n);
+                if(result){
+
+                    return true;
+                }
+
+                board[i][j]=0;
+
+            }
+
+        }
+
+        return false;
+
+    }
+
+    public static void placeNQueens(int n){
+
+        int board[][]=new int[n][n];
+        boolean ans= solve(board,0,n-1);
+
+    }
+
+}