HDU ACM 11 2073 无限的路

#include <iostream>#include <cmath>using namespace std;int main(){double Lu[3][3];int n;cin >> n;while (n--){cout << fixed;cout.precision(3);for (int i = 1; i <= 2; i++)cin >> Lu[i][1] >> Lu[i][2];double x, y;x = Lu[1][1] + Lu[1][2];y = Lu[2][1] + Lu[2][2];if (x == y){cout << sqrt((Lu[1][1] - Lu[2][1]) * (Lu[1][1] - Lu[2][1]) + (Lu[1][2] - Lu[2][2]) * (Lu[1][2] - Lu[2][2])) << endl;continue;}double sum = 0;if (x > y){swap(Lu[1][1], Lu[2][1]);swap(Lu[1][2], Lu[2][2]);swap(x, y);}sum = sqrt((Lu[1][1] - x) * (Lu[1][1] - x) + Lu[1][2] * Lu[1][2]) + sqrt((Lu[2][2] - y) * (Lu[2][2] - y) + Lu[2][1] * Lu[2][1]);for (int i = x + 1; i < y; i++)sum += sqrt(2 * i * i);for (int i = x; i < y; i++)sum += sqrt(i * i + (i + 1) * (i + 1));cout << sum << endl;}return 0;}