UVa 10310 Dog and Gopher(long long)

/*coder: ACboydate: 2010-3-21result: ACdescription: UVa 10310 Dog and Gopher*/#include <iostream>#include <cmath>using namespace std;struct Point {long long x;long long y;};Point points[1100];int n;Point dogPos;Point gopherPos;long long getDis(Point & a, Point & b) {return (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y);}int main() {#ifndef ONLINE_JUDGEfreopen("10310.txt", "r", stdin);#endifwhile (cin >> n) {int i, j;double x1, y1, x2, y2;cin >> x1 >> y1 >> x2 >> y2;gopherPos.x = x1 * 1000;gopherPos.y = y1 * 1000;dogPos.x = x2 * 1000;dogPos.y = y2 * 1000;for (i = 0; i < n; ++i) {cin >> x1 >> y1;points[i].x = x1 * 1000;points[i].y = y1 * 1000;}int ok = 0;int pos = -1;for (j = 0; j < n; ++j) {long long dis1 = getDis(dogPos, points[j]);long long dis2 = getDis(gopherPos, points[j]);if (dis2 * 4 <= dis1) {pos = j;ok = 1;break;}}if (ok) {printf("The gopher can escape through the hole at (%.3lf,%.3lf)./n", (double)points[pos].x / 1000, (double)points[pos].y / 1000);} else {cout << "The gopher cannot escape." << endl;}}}