程序，我们需要多少年买的房

都督发布于 2007-09-13 12:39， 552 次点击

有个问题是
假如２０１５年房价８０万，今年我大学毕业第一年月工资是２０００元，我的年工资增长率应该至少是多少，到２０１５年才能买的起房．
用循坏做呀
我想可以这样吗？
for(i=0;i<=7;i++)
{年工资＝年工资＊（１＋年增长率（求的））
if(年工资＜＝８０万)
｛break;｝
}
不行该怎么算呀

8 回复

HJin2007-09-13 13:03

you don't need to spend money on

0. food
1. housing
2. clothes
3. travel
4. socializing
5. etc.

?

Just a joke.

HJin2007-09-13 13:28

#include <stdio.h>
#include <math.h>

#define HOUSE_PRICE 800000.0
#define YEARS 2015-2007

/**
Your annual salary increase is 39.14%
Press any key to continue . . .
*/

float rate(float firstYearSalary)
{
float x=0.0;

do
{
x+=0.0001; // increase by 0.01%
}
while( firstYearSalary * (pow(1.0+x, YEARS)-1)/x < HOUSE_PRICE);

return x*100;
}

int main()
{
float firstYearSalary=24000.0;

printf("Your annual salary increase is %.2f%%\n", rate(firstYearSalary));

return 0;
}

snakeImao2007-09-13 14:50

"if(年工资＜＝８０万)"

照你的意思,2015年,这一年内至少要赚80万罗?
那你的年工资增长率不就是 55.01% 吗?

[此贴子已经被作者于2007-9-13 15:19:48编辑过]

都督2007-09-13 18:28

付首付,三十万

都督2007-09-13 18:35

do
{
x+=0.0001; // increase by 0.01%／／为什么是０．０００１呀，哪里的呀
}
while( firstYearSalary * (pow(1.0+x, YEARS)-1)/x < HOUSE_PRICE);

return x*100;

都督2007-09-13 18:47

哦知道了，是x从０．０００１开始增长，直到我的工资＞＝HOUSE_PRICE;
就能知道是增长率是多少了，你真聪明呀，

[此贴子已经被作者于2007-9-13 18:48:05编辑过]

都督2007-09-13 19:01

pow(1.0+x, YEARS)-1)/x
我认为这里应该是firstYearSalary＊（１．０＋x）的７次方
为什么你这是开方，能解释一下吗？谢谢

HJin2007-09-14 16:09

you need to work out the math.

denote the first year salary by a
then 2nd year salary is a(1+x);
3rd year is a(1+x)^2
...
nth year is a(1+x)^n

form year 1 to year n, you will earn (assume that you don't spend any money on food, clothes, etc)

a + a(1+x) + a(1+x)^2 + ...+ a(1+x)^n = a ((1+x)^(n+1) - 1 ) / x

if the last value >= house price, you own the house.