1935.cpp

这是哈尔滨工业大学acmOJ的源代码

/*  This Code is Submitted by wywcgs for Problem 1935 on 2006-08-10 at 20:19:32 */ 
#include <cstdio>
#include <algorithm>
using namespace std;
 
int main()
{
	int i, x[3], y[3];

	while(true) {
		int A = 0, E = 0;
		for(i = 0; i < 3; i++) scanf("%d %d", &x[i], &y[i]);
		bool end = true;
		for(i = 0; i < 3; i++) {
			if(x[i] != 0 || y[i] != 0) end = false;
			A += x[i]*y[(i+1)%3]-y[i]*x[(i+1)%3];
			int d, dx = abs(x[i]-x[(i+1)%3]), dy = abs(y[i]-y[(i+1)%3]);
			if(dx*dy == 0) E += dx+dy;
			else {
				int r = 1;
				while((d = __gcd(dx, dy)) != 1) { dx /= d; dy /= d; r *= d; }
				E += r;
			}
		}
		if(end) break;
		A = abs(A);
		int I = (A-E)/2 + 1;
		printf("%d\n", I);
	}
	
	return 0;
}