poj 2390 Bank Interest(计算本利和)

一、Description

Farmer John made a profit last year! He would like to invest it well but wonders how much money he will make. He knows the interest rate R (an integer between 0 and 20) that is compounded annually at his bank. He has an integer
amount of money M in the range 100..1,000,000. He knows how many years Y (range: 0..400) he intends to invest the money in the bank. Help him learn how much money he will have in the future by compounding the interest for each year he saves. Print an integer
answer without rounding. Answers for the test data are guaranteed to fit into a signed 32 bit integer.
Input

* Line 1: Three space-separated integers: R, M, and Y
Output

* Line 1: A single integer that is the number of dollars FJ will have after Y years.

二、题解

题目的提示很明显，计算过程如下：

INPUT DETAILS:

5% annual interest, 5000 money, 4 years

OUTPUT DETAILS:

Year 1: 1.05 * 5000 = 5250

Year 2: 1.05 * 5250 = 5512.5

Year 3: 1.05 * 5512.50 = 5788.125

Year 4: 1.05 * 5788.125 = 6077.53125

The integer part of 6077.53125 is 6077.

需要注意的是计算过程中间结果要用double存放。

三、java代码

import java.util.Scanner;

public class Main {

public static void main(String[] args)  {
Scanner sc = new Scanner(System.in);
int r,m,y,i;
double result,r1;
r=sc.nextInt();
m=sc.nextInt();
y=sc.nextInt();
r1=0.01 * r+1;
result=m;
for(i=0;i<y;i++){
result*=r1;
}
System.out.println((int)result);
}
}