Question

用Java编写一个方法 用来计算并输出： 1-1/2+1/3-1/4+1/5-1/6……-1/50

Answer 1

调用时n=50;
double s(int n){
int temp=1;
dobule sum=0;
for(int i=1;i<=n;i++){
sum+=temp*(1/i);
temp*=-1;
}
return sum;
}

Answer 2

我前段时间回答过类似的题目,可以参考下代码:**
* 1-1/2+1/3-1/4+...+1/100
*/
public static void main(String[] args) {
double a=0,b=0;
for(int i=1;i<=100;i++){
if(i%2==1){
a=a+(double)1/i;
}
else{
b=b+(double)1/i;
}
}
System.out.println(a-b);
}

Answer 3

public class Sum {
public static double sum(int n){
double sum=0;
double flag=1.0;
if(n==0){
System.out.println("Divide by zero!");
System.exit(0);
}
for(int i=1;i<=n;i++){
sum+=1/(i*flag);
flag*=-1;
}
return sum;
}
public static void main(String[] args){
System.out.println("sum="+sum(0));
}
}

Answer 4

double sum(int m) {
double sum = 0;
for (int i = 1; i <= 50; i++) {
if (i % 2 == 0)
sum -= 1 / i;

else
sum += 1 / i;

}

return sum;

}