uva 10573

這題有點賤，有可能輸入會有一個或兩個的情況，給切線長度或兩個r

//============================================================================
// Name        : Geometry Paradox.cpp
// Date : 2013/3/28 下午10:26:00
// Author : GCA
//============================================================================
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <climits>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cctype>
#include <utility>
using namespace std;
#ifdef ONLINE_JUDGE
#define ll "%lld"
#else
#define ll "%I64d"
#endif
typedef unsigned int uint;
typedef long long int Int;
#define Set(a,s) memset(a,s,sizeof(a))
#define Write(w) freopen(w,"w",stdout)
#define Read(r) freopen(r,"r",stdin)
#define Pln() printf("\n")
#define I_de(x,n)for(int i=0;i<n;i++)printf("%d ",x[i]);Pln()
#define De(x)printf(#x"%d\n",x)
#define For(i,x)for(int i=0;i<x;i++)
#define CON(x,y) x##y
#define Pmz(dp,nx,ny)for(int hty=0;hty<ny;hty++){for(int htx=0;htx<nx;htx++){\
    printf("%d ",dp[htx][hty]);}Pln();}
#define M 55
#define PII pair<int,int>
#define PB push_back
#define oo INT_MAX
#define Set_oo 0x3f
#define Is_debug true
#define debug(...) if(Is_debug)printf("DEBUG: "),printf(__VA_ARGS__)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define eps 1e-6
bool xdy(double x,double y){return x>y+eps;}
bool xddy(double x,double y){return x>y-eps;}
bool xcy(double x,double y){return x<y-eps;}
bool xcdy(double x,double y){return x<y+eps;}
int min3(int x,int y,int z){
    int tmp=min(x,y);
    return min(tmp,z);
}
int max3(int x,int y,int z){
    int tmp=max(x,y);
    return max(tmp,z);
}
double pi=acos(0)*2;
int main() {
    ios_base::sync_with_stdio(0);
    int n;
    scanf("%d%*c",&n);
    char str[1000];
    while(n--){
        gets(str);
        int r1,r2,r3;
        if(sscanf(str,"%d %d",&r1,&r2)==2){
            r3=r1+r2;
            double ans=((r3*r3)-(r1*r1)-(r2*r2))*pi;
            printf("%.4lf\n",ans);
        }else{
            sscanf(str,"%d",&r1);
            double ans=(r1*r1)*pi/8;
            printf("%.4lf\n",ans);
        }
    }

}