public class Main {
public static void main(String[] args) {
int[] ns = { 1, 4, 9, 16, 25 };
for (int i = ns.length - 1; i >= 0; i --) {
System.out.println(ns[i]); // 25 16 9 4 1
}
}
}
public class Main {
public static void main(String[] args) {
int[] ns = { 1, 4, 9, 16, 25 };
int sum = 0;
for (int n : ns) {
sum += n;
}
System.out.println(sum); // 55
}
}
public class Main {
public static void main(String[] args) {
double pi = 0;
for (int i = 1; ; i += 4) {
pi += (1.0 / i);
if (i < 0) {
break;
}
}
for (int i = 3; ; i += 4) {
pi -= (1.0 / i);
if (i < 0) {
break;
}
}
pi *= 4;
System.out.print(pi); // 3.141592652649746
}
}
唯情恋昉
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