Given two integers a and b, which can be positive or negative, find the sum of all the numbers between including them too and return it. If the two numbers are equal return a or b.
Note: a and b are not ordered!
Examples
get_sum(1, 0) == 1 // 1 + 0 = 1
get_sum(1, 2) == 3 // 1 + 2 = 3
get_sum(0, 1) == 1 // 0 + 1 = 1
get_sum(1, 1) == 1 // 1 Since both are same
get_sum(-1, 0) == -1 // -1 + 0 = -1
get_sum(-1, 2) == 2 // -1 + 0 + 1 + 2 = 2初級解法：
def get_sum(a,b):
c=0
if a==b:
return a
elif a>b:
for i in range(b,a+1):
c+=i
return c
elif a<b:
for i in range(a,b+1):
c+=i
return c大神解法：
def get_sum(a,b):
return sum(xrange(min(a,b), max(a,b)+1))
