# 對頭的數(shù)量進(jìn)行有效性判斷

while True:

? ? head = int(input("雞和兔的頭數(shù)和："))

if head>0:

break

else:

? ? ? ? print("輸入頭數(shù)有誤，請重新輸入！")

# 對腳的數(shù)量進(jìn)行有效性判斷while True:

? ? foot = int(input("雞和兔的腳數(shù)和："))

if foot>=head*2 and foot<=head*4:

break

else:

? ? ? ? print("輸入腳數(shù)有誤，請重新輸入！")

# 雞的個(gè)數(shù)ji = 0

while ji<=head:

? ? # 兔的個(gè)數(shù)tu = head - ji

if foot==ji*2+tu*4:

? ? ? ? print("雞有{}只，兔有{}只".format(ji,tu))

break

ji+=1

print("程序結(jié)束！")