cf559A

题意：求六边形里面三角形的个数。

   先补成大的正三角形，然后减去小的三个正三角形。

#include<iostream>#include<cstdio>#include<cmath>#include<cstdlib>#include<iomanip>#include<algorithm>#include<cctype>#include<stack>#include<queue>#include<string>#include<cstring>#include<iomanip>#include<set>#include<vector>#include<cstdio>#include<stack>#include<cstring>using namespace std;int main(){    int a,b,c,d,e,f;    cin>>a>>b>>c>>d>>e>>f;    int S=(c+d+e)*(c+d+e);    int s1=e*e;    int s2=c*c;    int s3=a*a;    int res=S-s1-s2-s3;    cout<<res<<endl;}