2954 Triangle 解题报告

/*Pick公式：整点多边形的面积=内部整点个数+边上的整点个数/2 - 1.*/#include<math.h>#include<stdio.h>#include<iostream>using namespace std;int _tmp;void swap(int &x,int &y){_tmp = x;x = y;y = _tmp;}int gcd(int x,int y){int r;if(x > y)swap(x,y);while((r = y % x) != 0){y = x;x = r;}return x;}int l(int x,int y){if(!x || !y)return abs(x+y);return gcd(abs(x),abs(y));}//计算面积double area(int a,int b,int c,int d,int e,int f){int x1 = a-c,x2 = b-d;int y1 = e-c,y2 = f-d;return fabs(1.0*x1*y2-x2*y1)/2;}int main(){double line,darea;int a,b,c,d,e,f;while(true){scanf("%d%d%d%d%d%d",&a,&b,&c,&d,&e,&f);if(!a && !b && !c && !d && !e && !f)return 0;line = l(a-c,b-d) + l(a-e,b-f) + l(c-e,d-f);line /= 2;darea = area(a,b,c,d,e,f);printf("%d/n",(int)(darea + 1.1 - line));}return 0;}//error: 2 tle + 7 wa//suikay 2954 Accepted 392K 0MS