Codility--- NumberOfDiscIntersections

// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(int[] A) {
        // write your code in Java SE 8
        int l = A.length;  
        int[] arrayIn = new int[l];  
        int[] arrayOut = new int[l];  
        int inNumContext = 0;  
        int result = 0;  
          
        for(int i = 0; i < l; i ++) {  
            int in = (i - A[i]) < 0 ? 0 : (i - A[i]);  
            // take care the (A[i] + i) exceeds the value of MAX int   
            // which will become minus int  
            int out = (A[i] + i > l - 1 || A[i] + i < 0) ? (l - 1) : (A[i] + i);  
            arrayIn[in] ++;  
            arrayOut[out] ++;  
        }  
          
          
        for(int i = 0; i < l; i ++) {  
            if(arrayIn[i] != 0) {  
                // previous circles times new coming circles  
                result += inNumContext * arrayIn[i];  
                // new coming circles group with each other  
                result += arrayIn[i] * (arrayIn[i] - 1) / 2;  
                  
                if (result > 10000000) {  
                    return -1;  
                }  
                  
                // add coming circles to inNumContext  
                inNumContext += arrayIn[i];  
            }  
            // minus leaving circles from inNumContext  
            inNumContext -= arrayOut[i];  
        }   
          
        return result;
    }
}