最后一个样例过不了的看看我的, b[i] 太大会导致求b[i] * (b[i] - 1)超过范围

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
static int[] a = new int [100010];
static long[] b = new long [100010];
public static void main(String[] args) throws IOException{
    String[] s1 = reader.readLine().split(" ");
    int n = Integer.parseInt(s1[0]);
    int k = Integer.parseInt(s1[1]);
    long res = 0;
    for (int i = 1; i <= n; i++) {
        a[i] = (a[i - 1] + Integer.parseInt(reader.readLine())) % k;
        b[a[i]] ++;
    }       
    b[0] ++;
    for(int i = 0; i < k ; i ++)
            if(b[i] > 1) {
                long temp = b[i] * (b[i] - 1) / 2;
                res += temp;

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