HDU 5666 Segment

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 1082    Accepted Submission(s): 398

Problem Description

 Please calculate how many nodes are in the delta and not on the segments,output answer mod P.

 

 

Input

10.

 

 

Output

 Output 1 number to each testcase,answer mod P.

 

 

Sample Input

1 2 107

 

 

Sample Output

0

 

题目就是求直线与坐标轴围成的区域内有多少个点（整数）我们可以发现 点的数量是成等差数列的  求和就ok了  注意数据范围 

import java.util.*;
import java.math.*;
public class Main {
    public static void main(String []args){
        Scanner cin=new Scanner(System.in);
        int n;
        BigInteger a,b,e;
        n=cin.nextInt();
        for(int i=1;i<=n;i++){
            a=cin.nextBigInteger();
            b=cin.nextBigInteger();
            BigInteger c=new BigInteger("2");
            BigInteger d=new BigInteger("1");
            a=a.subtract(c);
            e=a.multiply(a).add(a);
            e=e.divide(c);
            e=e.mod(b);
            System.out.println(e);
        }
    }

}