Question

用JAVA循环语句计算1+3-5+7-9+11-13.......+9999= 怎么写？

Answer 1

//1+3-5+7-9+11-13.......+9999
public static void main(String[] args){
int total = 0;
for (int i = 1; i <= 9999; ++i){
//奇数
if (i % 2 == 1){
//如果模4==1,则减法,如(5,9,13...)
if (i % 4 == 1){
total -= i;
}else{
total += i;
}
}
}
System.out.println(total);
}

结果为: 5000

Answer 2

int a=1;
int b=1;
int c=0;
while(a<10000){
if(b==1){
c=c+a;
}else if(b%2==0){
c=c+a;
}else{
c=c-a;
}
System.out.println(c);
a=a+2;
b=b+1;
}
System.out.println(c);

最脑残的办法。自己个人看吧。结果等于5002

Answer 3

public class C {

public static void main(String[] args) {

int sum = 1;
for(int i = 3, j = 1; i <= 9999; i= i+2){
if(j == 1){
sum = sum - i;
j = 0;
}else{
sum = sum + i;
j = 1;
}

}

System.out.println("1+3-5+7-9+11-13.......+9999=" + sum);

}

}

------------
1+3-5+7-9+11-13.......+9999=-5000

Answer 4

import java.util.Scanner;;

public class Add_Sub {
static Scanner in = null;
public Add_Sub() {
in = new Scanner(System.in);
}

public static void main(String[] args) {
Add_Sub add_Sub = new Add_Sub();
System.out.println("开始数：");
int begin = in.nextInt();
System.out.println("结束数：");
int end = in.nextInt();
int result = add_Sub.caculate(begin, end);
System.out.print("运算结果：\r\n"+result);

}

private int caculate(int begin,int end){
int result = 1;
char operator = '+';
for(int i = begin+2;i <= end;i=i+2){
if(operator=='+'){
result+=i;
operator='-';
}else if(operator=='-'){
result-=i;
operator='+';
}else{
System.out.println("运算符出错！");
break;
}
}
return result;
}
}

Answer 5

public class Test
{
public static void main(String[] args)
{
long num = 1;
int count = 0;
for(int i=3;i<=9999;i+=2){
if(count%2 == 0){
num +=i;

}else{
num -=i;
}
count++;

}
System.out.println("1+3-5+7-9+11-13.......+9999="+num);
}
}
结果为5002