To store the positions of palindromic sub - strings
let dp = new Array ( s . length ) ; for ( let i = 0 ; i < dp . length ; i ++ ) { dp [ i ] = new Array ( 2 ) ; } for ( let i = 0 ; i < dp . length ; i ++ ) { for ( let j = 0 ; j < dp . length ; j ++ ) { dp [ i ] [ j ] = 0 ; } } let st , end , i , len ;