CF#524-B

题目链接

http://codeforces.com/contest/1080/problem/B

思路

数学规律题

代码

#include<iostream>
using namespace std;
int main()
{
    int n;
    while(cin >> n)
    {
        int l, r;
        while(n--)
        {
            int ans = 0;
            cin >> l >> r;
            if(l & 1)
                ans = ((r - l + 1) & 1) ? ((r - l) / 2 - r) : (r - l + 1) / 2;
            else
                ans = ((r - l + 1) & 1) ? (-(r - l) / 2 + r) : (-(r - l + 1) / 2);
            cout << ans << endl;
        }
    }
    return 0;
}