subtracting c [ n ] and adding c [ 0 ] by 1 as ( x - 1 ) ^ n - ( x ^ n - 1 ) , here we are subtracting c [ n ] by 1 and adding 1 in expression .
c [ 0 ] = c [ 0 ] + 1 ; NEW_LINE c [ n ] = c [ n ] - 1 ; NEW_LINE