Algorithm written test surface Test _ Mall engage in activities, full 100 minus 30, full 200 minus 80, ask 1000 yuan the most can buy what money?

Algorithm written test surface Test _ Mall engage in activities, full 100 minus 30, full 200 minus 80, ask 1000 yuan the most can buy what money?

Solution Ideas:

1, first spend 1000 yuan, return (1000/200) *80 = 400

2, spend 400 yuan, return (400/200) *80 = 160;

3, borrow someone else 40 yuan, hand gather enough 200 yuan, return 80 yuan.

4, also give others 40 yuan, hand also has 40 yuan, also can buy 40 yuan of thing.

That is, a total of buy 1000+400+40+160+80-40=1640 yuan.

Is there a better way? If you have any, please correct me.

Algorithm written test surface Test _ Mall engage in activities, full 100 minus 30, full 200 minus 80, ask 1000 yuan the most can buy what money?