Lintcode-search 2D Matrix II

Write a efficient algorithm that searches for a value in a m x n matrix, return the occurrence of it.

This matrix has the following properties:

* Integers in each row is sorted from left to right.

* Integers in each column is sorted from up to bottom.

* No duplicate integers in each row or column.

Example

Consider the following matrix:

[

[1, 3, 5, 7],

[2, 4, 7, 8],

[3, 5, 9, 10]

]

Given target = 3, return 2.

Challenge

O (m+n) Time and O (1) Extra space

Solution:

1  Public classSolution {2     /**3      * @parammatrix:a List of lists of integers4      * @param: A number you want to search in the matrix5      * @return: An integer indicate the occurrence of target in the given matrix6      */7      Public intSearchmatrix (arraylist<arraylist<integer>> Matrix,inttarget) {8         intm =matrix.size ();9         if(m==0)return0;Ten         intn = matrix.get (0). Size (); One         if(n==0)return0; A          -         returnSearchmatrixrecur (matrix,target,0,0,m-1,n-1); -     } the  -      Public intSearchmatrixrecur (arraylist<arraylist<integer>> Matrix,intTargetintX1,intY1,intX2,inty2) { -         if(x2<x1 | | y2<y1)return0; -  +         if(X1==x2 && y1==y2) -             if(Matrix.get (x1). Get (y1) ==target)return1; +             Else return0; A  at         intMidx = (x1+x2)/2; -         intMidy = (y1+y2)/2; -         intMidval =Matrix.get (MIDX). get (Midy); -         intres = 0; -  -         if(midval==target) { in             //We have a to search all of the four sub matrix. -res++; toRes + = Searchmatrixrecur (matrix,target,x1,y1,midx-1,midy-1); +Res + = Searchmatrixrecur (matrix,target,midx+1,midy+1, x2,y2); -Res + = Searchmatrixrecur (Matrix,target, (x1+x2)/2+1,y1,x2, (y1+y2)/2-1); theRes + = Searchmatrixrecur (matrix,target,x1, (Y1+y2)/2+1, (x1+x2)/2-1, y2); *}Else if(midval>target) { $             intLEFTX = (x1+x2)/2;Panax Notoginseng             intLefty =Y1; -             intUpX =X1; the             intUpy = (y1+y2)/2; +             if(Target==matrix.get (LEFTX). Get (lefty)) res++; A             if(Target==matrix.get (UpX). Get (Upy)) res++; the             if(Target <= matrix.get (LEFTX). Get (lefty) && target <=Matrix.get (UpX). Get (Upy)) { +Res + = Searchmatrixrecur (matrix,target,x1,y1,midx-1,midy-1); -}Else if(Target <=Matrix.get (LEFTX). Get (lefty)) { $Res + = Searchmatrixrecur (Matrix,target,x1,y1, (x1+x2)/2-1, y2); $}Else if(Target <=Matrix.get (UpX). Get (Upy)) { -Res + = Searchmatrixrecur (matrix,target,x1,y1,x2, (y1+y2)/2-1); -}Else { theRes + = Searchmatrixrecur (matrix,target,x1,y1,x2, (y1+y2)/2-1); -Res + = Searchmatrixrecur (Matrix,target,upx,upy, (x1+x2)/2-1, y2);Wuyi             } the}Else { -             intRIGHTX = (x1+x2)/2; Wu             intrighty =Y2; -             intLOWX =x2; About             intLowY = (y1+y2)/2; $             if(Target==matrix.get (RIGHTX). Get (righty)) res++; -             if(Target==matrix.get (LOWX). Get (LowY)) res++; -             if(Target >= matrix.get (RIGHTX). Get (righty) && target >=Matrix.get (LOWX). Get (LowY)) { -Res + = Searchmatrixrecur (matrix,target,midx+1,midy+1, x2,y2); A}Else if(Target >=Matrix.get (RIGHTX). Get (righty)) { +Res + = Searchmatrixrecur (Matrix,target, (x1+x2)/2+1, y1,x2,y2); the}Else if(Target >=Matrix.get (LOWX). Get (LowY)) { -Res + = Searchmatrixrecur (Matrix,target, X1, (y1+y2)/2+1, x2, y2); $}Else { theRes + = Searchmatrixrecur (Matrix,target, (x1+x2)/2+1, Y1, lowx, LowY); theRes + = Searchmatrixrecur (Matrix,target, X1, (y1+y2)/2+1, x2, y2); the             } the  -         } in         returnRes; the     } the}

Lintcode-search 2D Matrix II