Number of paths with exactly k coins | A Naive Recursive Javascript program to count paths with exactly ' k ' coins ; Recursive function to count paths with sum k from ( 0 , 0 ) to ( m , n ) ; Base cases ; ( m , n ) can be reached either through ( m - 1 , n ) or through ( m , n - 1 ) ; A wrapper over pathCountRec ( ) ; Driver code
let R = 3 ; let C = 3 ; function pathCountRec ( mat , m , n , k ) { if ( m < 0 n < 0 ) return 0 ; if ( m == 0 && n == 0 ) return ( k == mat [ m ] [ n ] ) ; return pathCountRec ( mat , m - 1 , n , k - mat [ m ] [ n ] ) + pathCountRec ( mat , m , n - 1 , k - mat [ m ] [ n ] ) ; } function pathCount ( mat , k ) { return pathCountRec ( mat , R - 1 , C - 1 , k ) ; } let k = 12 ; let mat = [ [ 1 , 2 , 3 ] , [ 4 , 6 , 5 ] , [ 3 , 2 , 1 ] ] ; document . write ( pathCount ( mat , k ) ) ;