dp [ i ] [ j ] != INT_MAX denotes that cell ( i , j ) can be reached from cell ( 0 , 0 ) and the other half of the condition finds the cell on the right that can be reached from ( i , j )
if ( dp [ i ] [ j ] != INT_MAX && ( j + mat [ i ] [ j ] ) < n && ( dp [ i ] [ j ] + 1 ) < dp [ i ] [ j + mat [ i ] [ j ] ] ) dp [ i ] [ j + mat [ i ] [ j ] ] = dp [ i ] [ j ] + 1 ;