How can I determine all possible ways a subsequence can be removed from a sequence?

Question

Given two sequences, A and B, how can I generate a list of all the possible ways that B can be removed from A?

For example, In JavaSc

Answer 1

My aim was to create and call functions as little as possible. This seems to work. Could definitely be cleaned up. Something to play around with...

function removeSubSeq( seq, sub ) {

    var arr,
        sub_v,
        sub_i = 0,
        seq_i,
        sub_len = sub.length,
        sub_lenm1 = sub_len - 1,
        seq_len = seq.length,
        pos = {},
        pos_len = [],
        c_pos,
        map_i = [],
        len,
        r_pos,
        sols = [],
        sol;

    do {

        map_i[ sub_i ] = 0;
        sub_v = sub[ sub_i ];

        if( pos[ sub_v ] ) {

            pos_len[ sub_i ] = pos_len[ sub_i - 1 ];
            continue;
        
        }

        arr = pos[ sub_v ] = [];

        c_pos = 0;

        seq_i = seq_len;

        while( seq_i-- ) {

            if( seq[ seq_i ] === sub_v ) {
                
                arr[ c_pos++ ] = seq_i;

            }

        }

        pos_len[ sub_i ] = arr.length;

    } while( ++sub_i < sub_len );

    len = pos[ sub[ 0 ] ].length;

    while( map_i[ 0 ] < len ) {

        sub_i = 0;
        arr = [];

        do {

            r_pos = pos[ sub[ sub_i ] ][ map_i[ sub_i ] ];
            
            if( sub_i && r_pos <= arr[ sub_i - 1] ) break;
            
            arr.push( r_pos );
        
        } while( ++sub_i < sub_len );

        if( sub_i === sub_len ) {
            
            sol = seq.slice( 0 );

            while( sub_i-- ) sol.splice( arr[ sub_i ], 1 );

            sols.push( sol );
        
        }

        sub_i = sub_lenm1;

        while( ++map_i[ sub_i ] === pos_len[ sub_i ] ) {
            if( sub_i === 0 ) break;
            map_i[ sub_i-- ] = 0;
        }

    } while( map_i[ 0 ] < len );

    return sols;

}

console.log(JSON.stringify(removeSubSeq([1,2,1,3,1,4,4], [1,4,4])));
console.log(JSON.stringify(removeSubSeq([8,6,4,4], [6,4,8])));
console.log(JSON.stringify(removeSubSeq([1,1,2], [1])));
console.log(JSON.stringify(removeSubSeq(['a','g','b','a','b','c','c'], ['a','b','c'])));