text: dp2 [ i ] to store the no of ways to get to a bad shift in i moves
code: let dp1 = Array . from ( { length : k + 1 } , ( _ , i ) => 0 ) ; let dp2 = Array . from ( { length : k + 1 } , ( _ , i ) => 0 ) ; if ( s == t ) { dp1 [ 0 ] = 1 ; dp2 [ 0 ] = 0 ; } else { dp1 [ 0 ] = 0 ; dp2 [ 0 ] = 1 ; }