# 求1-2+3-4+5.....99的所有数的和（含等式）
s = ""
sum = 0
start = 1
while start < 100:
temp = start % 2
if temp == 1:
if start == 1:
s = str(start)
else:
s = s + "+" + str(start)
sum = sum + start
else:
s = s + "-" + str(start)
sum = sum - start
start += 1
print(s)
print(start)
# 求1-2+3-4+5.....99的所有数的和（不含等式）
sum = 0
start = 1
while start < 100:
temp = start % 2
if temp == 1:
sum = sum + start
else:
sum = sum - start
start += 1
print(sum)
print(start)
1 # 求1-2+3-4+5.....99的所有数的和（含等式） 2 s = "" 3 4 sum = 0 5 start = 1 6 7 while start < 100: 8 temp = start % 2 9 if temp == 1: 10 if start == 1: 11 s = str(start) 12 else: 13 s = s + "+" + str(start) 14 sum = sum + start 15 else: 16 s = s + "-" + str(start) 17 sum = sum - start 18 start += 1 19 20 print(s) 21 print(start) 22 23 24 25 # 求1-2+3-4+5.....99的所有数的和（不含等式） 26 sum = 0 27 start = 1 28 29 while start < 100: 30 temp = start % 2 31 if temp == 1: 32 sum = sum + start 33 else: 34 sum = sum - start 35 start += 1 36 37 print(sum) 38 print(start)