import java.util.Scanner;

public class Main
{
public static void main(String[] args)
{
Scanner scan=new Scanner(System.in);
int n=scan.nextInt();
Scanner scan1=new Scanner(System.in);
String str=scan1.nextLine();
String s=" ";
String[] ss=str.split(s);
int[] arr=new int[n];
for(int i=0;i<n;i++)
{
int j=Integer.valueOf(ss[i]);
arr[i]=j;
}
int num=0;
for(int a=0;a<n;a++)
{
a:for(int b=0;b<n;b++)
{
if(b==a) continue;
for(int c=0;c<n;c++)
{
if(c==a || c==b) continue;
if(arr[b]+arr[c]==arr[a])
{
num++;
break a;
}
}
}
}System.out.println(num);
}
}

记录信息
评测状态    Accepted
题目  P1911 珠心算测验
递交时间    2016-07-22 16:06:08
代码语言    Java
评测机 ShadowShore
消耗时间    1184 ms
消耗内存    43024 KiB
评测时间    2016-07-22 16:06:10
评测结果
编译成功

测试数据 #0: Accepted, time = 140 ms, mem = 43020 KiB, score = 10
测试数据 #1: Accepted, time = 109 ms, mem = 43024 KiB, score = 10
测试数据 #2: Accepted, time = 109 ms, mem = 43016 KiB, score = 10
测试数据 #3: Accepted, time = 109 ms, mem = 43012 KiB, score = 10
测试数据 #4: Accepted, time = 140 ms, mem = 43012 KiB, score = 10
测试数据 #5: Accepted, time = 109 ms, mem = 43020 KiB, score = 10
测试数据 #6: Accepted, time = 109 ms, mem = 43016 KiB, score = 10
测试数据 #7: Accepted, time = 109 ms, mem = 43020 KiB, score = 10
测试数据 #8: Accepted, time = 125 ms, mem = 43012 KiB, score = 10
测试数据 #9: Accepted, time = 125 ms, mem = 43016 KiB, score = 10
Accepted, time = 1184 ms, mem = 43024 KiB, score = 100
代码
import java.util.Scanner;
class Main {
public static void main(String[] args) {
    Scanner s = new Scanner(System.in);
    int num = 0;
    int a[];
    int y[];
    y = new int[101];
    a = new int[101];
    num = s.nextInt();
    int CNT = 0;
    for (int i = 0; i < num; i++) {
        a[i] = s.nextInt();
    }
    for (int i = 0; i < num; i++) {
        for (int j = 0; j < num ; j++) {
            for (int k = 0; k < num  && k != j; k++) {
                if (a[i] == a[j] + a[k]) {
                    y[i] = 1;
                }

            }
        }
    }
    for (int i = 0;i < num;i++)
      if (y[i] == 1) CNT++;
    System.out.println(CNT);
}
}

恭喜自言自语

好吧我傻了只有下标没有排除两数相同的情况

···
import java.util.Scanner;

class Main {

public static void main(String[] args) {
Scanner s = new Scanner(System.in);
int num = 0;
int a[];
a = new int[101];
num = s.nextInt();
int CNT = 0;
for (int i = 0; i < num; i++) {
a[i] = s.nextInt();
}
for (int i = 0; i < num; i++) {
for (int j = 0 ; j < num ; j++) {
for (int k = 0; k < num && k != j; k++) {
if (a[i] == a[j] + a[k]) {
CNT++;
System.out.println(a[i]+"="+a[j]+"+"+a[k]);
}

}
}
}
System.out.println(CNT);
}
}
···

附上测试版。。
import java.util.Scanner;

class Main {

public static void main(String[] args) {
Scanner s = new Scanner(System.in);
int num = 0;
int a[];
a = new int[101];
num = s.nextInt();
int CNT = 0;
for (int i = 0; i < num; i++) {
a[i] = s.nextInt();
}
for (int i = 0; i < num; i++) {
for (int j = 0 ; j < num ; j++) {
for (int k = 0; k < num && k != j; k++) {
if (a[i] == a[j] + a[k]) {
CNT++;
System.out.println(a[i]+"="+a[j]+"+"+a[k]);
}

}
}
}
System.out.println(CNT);
}
}