Find number of subarrays with even sum | Python 3 program to count number of sub - arrays whose sum is even using brute force Time Complexity - O ( N ^ 2 ) Space Complexity - O ( 1 ) ; Find sum of all subarrays and increment result if sum is even ; Driver code
def countEvenSum ( arr , n ) : NEW_LINE INDENT result = 0 NEW_LINE for i in range ( 0 , n , 1 ) : NEW_LINE INDENT sum = 0 NEW_LINE for j in range ( i , n , 1 ) : NEW_LINE INDENT sum = sum + arr [ j ] NEW_LINE if ( sum % 2 == 0 ) : NEW_LINE INDENT result = result + 1 NEW_LINE DEDENT DEDENT DEDENT return ( result ) NEW_LINE DEDENT if __name__ == ' _ _ main _ _ ' : NEW_LINE INDENT arr = [ 1 , 2 , 2 , 3 , 4 , 1 ] NEW_LINE n = len ( arr ) NEW_LINE print ( " The ▁ Number ▁ of ▁ Subarrays " , " with ▁ even ▁ sum ▁ is " , countEvenSum ( arr , n ) ) NEW_LINE DEDENT