java 如何使用扫描仪和 for 循环（无数组）查找第二大数
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How to find second largest number using Scanner and for loop(no array)
提问by landscape
So I can easily accomplish task to find largest number and then if can be divided by three, print out. But do not know how to find second largest number from users sequence. Thanks for any hints!
所以我可以轻松地完成查找最大数的任务，然后如果可以除以三，则打印出来。但是不知道如何从用户序列中找到第二大数字。感谢您的任何提示！
public class SecondLargest {
public static void main(String[] args) {
int max = 0;
Scanner scan = new Scanner(System.in);
System.out.println("How many numbers?");
int n = scan.nextInt();
System.out.println ("Write numbers: ");
for(int i=0; i<n; i++){
int c = scan.nextInt();
if(c>=max && c%3 == 0){
max = c;
}
else
System.out.println("There is no such number.");
}
System.out.println(max);
}
}
回答by Bozho
int secondLargest = 0;
.....
for (..) {
....
if (c % 3 == 0) {
if (c >= max) {
secondLargest = max;
max = c;
}
if (c >= secondLargest && c < max) {
secondLargest = c;
}
}
....
}
回答by Drakosha
You just need to keep 2 variables, one for maximum and another for second_maximum and update them appropriately.
您只需要保留 2 个变量，一个用于最大值，另一个用于 second_maximum 并适当更新它们。
For a more general approach, take a look at selection algorithms
对于更通用的方法，请查看选择算法
回答by Jay Shah
Below code will work
import java.util.Scanner;
public class Practical4 {
public static void main(String a[]) {
int max = 0, second_max = 0, temp, numbers;
Scanner scanner = new Scanner(System.in);
System.out.println("How many numbers do you want to enter?");
numbers = scanner.nextInt();
System.out.println("Enter numbers:");
for (int i = 0; i < numbers; i++) {
if (i == 0) {
max = scanner.nextInt();
} else {
temp = scanner.nextInt();
if (temp > max) {
second_max = max;
max = temp;
}
else if(temp>second_max)
{
second_max=temp;
}
}
}
scanner.close();
System.out.println("Second max number is :" + second_max);
}
}
