四则运算--计应192黄慧娟
需求分析：作为一名小学家长，希望软件能自动给出一组100以内的加减乘除，做出判断，以便减轻我的负担。
psp：
具体代码：
package szys;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (true){
int x, y, z;
System.out.println("欢迎使用口算练习系统");
System.out.println("1、加法练习");
System.out.println("2、减法练习");
System.out.println("3、乘法练习");
System.out.println("4、除法练习");
System.out.print("请选择需要练习的序号:");
z = sc.nextInt();
System.out.print("请选择需要练习的次数:");
int count = sc.nextInt();
if (z == 1){
System.out.print("您选择了加法练习");
while(count != 0 ){
System.out.println("当前剩余练习次数:" + count);
x = (int) (Math.random() * 50);
y = (int) (Math.random() * 50);
System.out.print(x + "+" + y + "=");
int result = sc.nextInt();
if (result != (x + y)){
System.out.println("回答错误,正确答案:" + (x + y));
}else {
System.out.println("回答正确");
}
count--;
}
}else if (z == 2){
System.out.print("您选择了减法练习");
while (count != 0){
System.out.println("当前剩余练习次数:" + count);
x = (int) (Math.random() * 100);
y = (int) (Math.random() * 100);
while(y > x){
x = (int) (Math.random() * 100);
}
System.out.print(x + "-" + y + "=");
int result = sc.nextInt();
if (result != (x - y)){
System.out.println("回答错误，正确答案:" + (x - y));
}else {
System.out.println("回答正确");
}
count--;
}
}else if (z == 4){
System.out.println("您选择了除法练习");
System.err.println("除法的运算结果只能为整数！！！");
while (count != 0){
System.out.println("当前剩余练习次数:" + count );
x = (int) (Math.random() * 100);
y = (int) (Math.random() * 10);
if (y == 0){
y = (int) (Math.random() * 10);
}
System.out.print(x + " / " + y + "=");
System.out.println();
System.out.println();
/*String remove = String.valueOf((Integer)(x / y));*/
/*String more = String.valueOf((Integer) (x % y));*/
int remove = x / y;
int more = x % y;
String s;
Double DoubleResult = null;
int result = 0;
if (more == 0){
s = String.valueOf(remove);
result = sc.nextInt();
}else {
s = remove + "." + more;
DoubleResult = sc.nextDouble();
}
String StrResult = result + "";
String StrDoubleResult = DoubleResult + "";
/*System.out.println("result:" + result);
System.out.println("s:" + s);
System.out.println("remove:" + remove);
System.out.println("more:" + more);*/
if (s.equals(StrResult)){
System.out.println("回答正确");
}else if (s.equals(StrDoubleResult)){
System.out.println("回答正确");
}else {
System.out.println("回答错误，正确答案:" + s);
}
count--;
}
}else if (z == 3){
System.out.print("您选择了乘法练习");
while (count != 0){
System.out.println("当前剩余练习次数:" + count);
x = (int) (Math.random() * 10);
y = (int) (Math.random() * 10);
System.out.print(x + " x " + y + "=");
int result = sc.nextInt();
if (result != (x * y)){
System.out.println("回答错误,正确答案:" + (x * y));
}else {
System.out.println("回答正确");
}
count--;
}
}else {
System.out.println("您选择的序号有误或非法，请重新输入！！！！ ");
}
}
}
}
