import java.util.Scanner;public class ch {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);System.out.println("复利计算器：计算复利终值请按1,计算本金请按2；股票投资：计算时间请按3，计算报酬率请按4，计算资产总值请按5" );int num=scanner.nextInt();//选择计算对象单利终值if (num == 1) {double N = 1, sum;System.out.print("请输入本金：");double money = scanner.nextDouble();System.out.print("请输入存钱年数：");int years = scanner.nextInt();System.out.print("请输入利率：");double r = scanner.nextDouble();sum = money + money * years * r;System.out.println("单利终值为：" + sum);sum = 0;for (int i = 1; i <= years; i++) {N = (1 + r) * N;}sum = N * money;System.out.println("复利终值为：" + sum);}//选择计算对象应投入的本金if (num == 2) {double N = 1, money;System.out.print("请输入复利终值：");double sum = scanner.nextDouble();System.out.print("请输入存钱年数：");int years = scanner.nextInt();System.out.print("请输入利率：");double r = scanner.nextDouble();for (int i = 1; i <= years; i++) {N = (1 + r) * N;}money = sum / N;System.out.println("应投入的本金为：" + money);}//选择计算对象需要时间if (num == 3) {double years;System.out.print("请输入本金：");double money = scanner.nextDouble();System.out.print("请输入最后得到资产总值：");double sum = scanner.nextDouble();System.out.print("请输入利率：");double r = scanner.nextDouble();        years = sum / (money * r);System.out.println("时间为（年）：" + years);}//选择计算对象利率if (num == 4) {double r;System.out.print("请输入本金：");double money = scanner.nextDouble();System.out.print("请输入最后得到资产总值：");double sum = scanner.nextDouble();System.out.print("请输入存钱年数：");int years = scanner.nextInt();r=sum/(money*years);System.out.println("利率为：" + r);}//选择计算对象利率资产总值if (num == 5){double sum;System.out.print("请输入本金：");double money = scanner.nextDouble();System.out.print("请输入利率：");double r = scanner.nextDouble();System.out.print("请输入存钱年数：");int years = scanner.nextInt();sum=money*r*years;System.out.println("若投资本金固定不变，则资产总值为：" + sum);sum=0;for(int i=1;i<=years;i++){sum=money*r*1;money=sum;                }System.out.println("若连本带利投资，则资产总值为：" + sum);}}}