一定要相信水题真的很水
POJ-2546
1 #include<iostream> 2 #include<stdio.h> 3 #include<cmath> 4 5 using namespace std; 6 7 #define PI acos(double(-1)) 8 9 int main() 10 { 11 double x1, y1, r1, x2, y2, r2; 12 cin>>x1>>y1>>r1>>x2>>y2>>r2; 13 double l = sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)); 14 double r = r1>r2? r2:r1; 15 if(l<=abs(r1-r2)) 16 printf("%.3lf\n",r*r*PI); 17 else if(l>=r1+r2) 18 printf("%.3lf\n",0); 19 else 20 { 21 double ang1 = acos((r1*r1+l*l-r2*r2)/(2*r1*l)); 22 double ss1 = r1*r1*ang1; 23 double ang2 = acos((r2*r2+l*l-r1*r1)/(2*r2*l)); 24 double ss2 = r2*r2*ang2; 25 double s1 = ss1 - r1*sin(ang1)*l/2; 26 double s2 = ss2 - r2*sin(ang2)*l/2; 27 printf("%.3lf",s1+s2); 28 } 29 return 0; 30 }
单纯的靠高中数学就切掉了。
