js array algorithm title 01

Title: generating a random integer type array of length 10 of, for example, [2, 10, 3, 4, 5, 11, 10, 11, 20 ], which are arranged in the following a new array, a new array of requirements, e.g. [[2, 3, 4, 5], [10, 11], [20]]. 




answer:

function formArray (ARR) { 
            const sortedArr = Array.from ( new new the Set (ARR)) Sort ((A, B) => A -. B);
             // define a Map 
            const = Map new new the Map (); 
            
            sortedArr.forEach ((V) => {
                 // get the index 
                const Math.floor Key = (V / 10 );
                 // get into map the subscript value 
                const Group = as map.get (Key) || [];
                 / / Push current value 
                group.push (V);
                 // refresh target current value map 
                 map.set (key, group);
            }); 
            // deconstruction returned array 
            return [... map.values ()]; 
        } 

        // find the continuous version 
        function formArray1 (ARR) { 
            const sortedArr = Array.from ( new new the Set (ARR)) Sort ((. a, B) => a - B); 
    
            return sortedArr.reduce ((ACC, CUR) => {
                 // get the current array and finally a last array value 
                const lastArr = acc.slice () pop ( ). || []; 
                const lastval = lastArr.slice () POP ();.
                 // lastval = null this judgment of undetermined significance, intuitively, even if the first cycle is not null, but undefined! 
                IF (lastval! = nullCUR && - === lastval. 1 ) {
                     // throw a last array in 
                    lastArr.push (CUR); 
                } the else {
                     // the last memory array becomes an up 
                    acc.push ([cur]); 
                } 

                return ACC; 
            }, []); 
        } 

        function genNumArray (NUM, Base = 100 ) {
             return Array.from ({length: NUM}, () => Math.floor (Math.random () * Base)); 
        } 

        const ARR = genNumArray (10, 20 is); // [2, 10,. 3,. 4,. 5,. 11, 10,. 11, 20 is]; 
        const = RES formArray (ARR);
        const res1 = formArray1(arr);

        console.log(`res ${JSON.stringify(res)}`);