算不上几何的水题
第一种为（int)a*(int)b；
第二种分宽高交换两种讨论。
每一个的高度除第一个为1外其它的都可以看着b/sqrt(3.0)/2;
1 #include <iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 #include<stdlib.h> 6 #include<vector> 7 #include<cmath> 8 #include<queue> 9 #include<set> 10 using namespace std; 11 #define N 100000 12 #define LL long long 13 #define INF 0xfffffff 14 const double eps = 1e-8; 15 const double pi = acos(-1.0); 16 const double inf = ~0u>>2; 17 int dcmp(double x) 18 { 19 if(fabs(x)<eps) return 0; 20 else return x<0?-1:1; 21 } 22 int solve(double a,double b,int ta,int tb) 23 { 24 if(dcmp(a-1)<0||dcmp(b-1)<0) return 0; 25 int sum2; 26 int k = (b-1)/(sqrt(3.0)/2)+1; 27 if(dcmp(a-ta-0.5)>=0) 28 sum2 = k*ta; 29 else 30 sum2 = (k+1)/2*ta+k/2*(ta-1); 31 return sum2; 32 } 33 int main() 34 { 35 double a,b; 36 while(scanf("%lf%lf",&a,&b)!=EOF) 37 { 38 int ta = int(a+eps); 39 int tb = int(b+eps); 40 int sum1 = ta*tb; 41 int sum2 = solve(a,b,ta,tb); 42 swap(a,b); 43 sum2 = max(sum2,solve(a,b,tb,ta)); 44 if(sum1>=sum2) 45 printf("%d grid ",sum1); 46 else 47 printf("%d skew ",sum2); 48 } 49 return 0; 50 }