sumArray_divide

function sumArray(arr:number[],size:number):number{
    if(size==-1){
        return 0;
    }
    return arr[size]+sumArray(arr,size-1);
}

function checkDiv(arr:number[]):number{
    return sumArray(arr,arr.length-1)%3==0?1:0;
}

let arr:number[] = [1,2,3,4,5];
console.log(checkDiv(arr));