Minimum value of K such that sum of cubes of first K natural number is greater than equal to N | Java program to determine the minimum value of K such that the sum of cubes of first K natural number is greater than or equal to N ; Function to determine the minimum value of K such that the sum of cubes of first K natural number is greater than or equal to N ; Left bound ; Right bound ; Variable to store the answer ; Applying binary search ; Calculating mid value of the range ; If the sum of cubes of first mid natural numbers is greater than equal to N iterate the left half ; Sum of cubes of first mid natural numbers is less than N , then move to the right segment ; Driver code
class GFG { static int binary_searched_find_x ( int k ) { int l = 0 ; int r = k ; int ans = 0 ; while ( l <= r ) { int mid = l + ( r - l ) / 2 ; if ( Math . pow ( ( ( mid * ( mid + 1 ) ) / 2 ) , 2 ) >= k ) { ans = mid ; r = mid - 1 ; } else { l = mid + 1 ; } } return ans ; } public static void main ( String [ ] args ) { int N = 100 ; System . out . println ( binary_searched_find_x ( N ) ) ; } }