Find a number in sorted multidimentional array with binary search

Question

we got an increasing sorted multidimensional array for example:

int[][] mat = {{1,2,3,4},
{5,6,7,8},
{9,10,11,12},
{13,14,15,16}};

How can

Answer 1

Use java.util.Arrays. Use Arrays.binarySearch() function on flattened matrix:

int[][] mat = {{1,2,3,4},
{5,6,7,8},
{9,10,11,12},
{13,14,15,16}};


int key = 3;
int[] oneDArray = new int[mat[0].length*mat[0].length];

int s = 0;
for(int i = 0; i < mat[0].length; i ++) 
    for(int j = 0; j < mat[0].length; j ++){                           
        oneDArray[s] = mat[i][j];
        s++;
    } 


int found = Arrays.binarySearch(oneDArray, key);
if(found > -1){
     System.out.println(found/ mat[0].length + "," + found % mat[0].length);    
}

And the demo: https://ideone.com/bFZVMs