Minimum count of numbers required ending with 7 to sum as a given number | Function to return the count of minimum numbers ending with 7 required such that the sum of these numbers is n ; hasharr [ i ] will store the minimum numbers ending with 7 so that it sums to number ending with digit i ; Its always possible to write numbers > 69 to write as numbers ending with 7 ; If the number is atleast equal to the sum of minimum numbers ending with 7 ; Driver code
function minCount ( n ) { let hasharr = [ 10 , 3 , 6 , 9 , 2 , 5 , 8 , 1 , 4 , 7 ] ; if ( n > 69 ) return hasharr [ n % 10 ] ; else { if ( n >= hasharr [ n % 10 ] * 7 ) return ( hasharr [ n % 10 ] ) ; else return - 1 ; } } let n = 38 ; document . write ( minCount ( n ) ) ;