poj 2924 Gauß in Elementary School

#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;

int main()
{
    int tc, c = 0;
    long long sum, tmp1, tmp2, n , m;
    cin >> tc;
    while (tc--){
          c++;
          cin >> n >> m;
          if (n > 0 && m > 0){
                tmp1 = (n+m);
                tmp2 = (m-n+1);
                sum = tmp1 * tmp2 / 2;
          }
          else if (n < 0 && m < 0){
               n = abs(double(n));
               m = abs(double(m));
               tmp1 = (n+m);
               tmp2 = (n-m+1);
               sum = tmp1 * tmp2 / 2;
               sum = -sum;
          }
          else{
                 n = abs(double(n));
                 m = abs(double(m));
                 if (n > m){
                       tmp1 = (n+m+1);
                       tmp2 = (n-m);
                       sum = tmp1 * tmp2 / 2;
                       sum = -sum;
                 }
                 else{
                       tmp1 = (n+m+1);
                       tmp2 = (m-n);
                       sum = tmp1 * tmp2 / 2;
                 }                    
          }
          printf("Scenario #%d:\n%lld\n\n", c, sum);
    }
    system("pause");
}