练习一

str=input(‘please input your numbers: ‘)
numbers=str.split(‘,‘)
numbers=list(map(float,numbers))
sum=input(‘please input your target: ‘)
sum=int(sum)

i=0
length=len(numbers)
for x in numbers:                 
    i2=i+1   
    if i2<length:
        for yi in range(i2,length):
            target=numbers[yi]+x
            if target==sum:
                print(numbers.index(x),yi)
        i=i+1
print(‘finished!‘)