Find out whether the number exists from the matrix

subject ： A matrix , Increase from left to right , Increase from top to bottom ;
Look in the matrix , Whether the given number exists ;

analysis ： Look at the matrix from left to right ： In the rightmost row of the matrix , Is the largest in each row ,（ Here comes the soul painter ） Pictured

The first point in the upper right corner （ Referred to as A Click on it. ）, There is a property , If you compare A It's a little big , If you can't find the number in the first row, you can only find it in the next row ; If you compare A Small , Can only move to the left ; When moving to the next point , You can still continue to judge with the above ideas ;
So this is the way to think about it , The worst result , Is in the lower left corner of the matrix ： find / Did not find ;
that , The boundary of this algorithm is easy to determine ;

```
public boolean  find(int target ,int[][] a){

    int m = 0;
    int n = a[0].length-1;
    while(true){
        if(m >a.length-1 || n <0){// The border ,
            return false;
        }
        if(target == a[m][n]){// eureka , Go straight back to 
            return true;
        }

        if(target < a[m][n]){// Move left 
            n--;
            continue;
        }

        if(target > a[m][n]){// Move right 
            m++;
            continue;
        }


    }





}