Codeforces Beta Round #1

A

/*************************************************************************
 > File Name: A.cpp
 > Author: opas_chenxin
 > Mail: 1017370773@qq.com 
 > Created Time: 2016年05月06日 星期五 02时22分23秒    
*************************************************************************/
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<cmath>
using namespace std;
int main(int argc, char *argv[])
{
    int n,m,a;
    
    while(scanf("%d%d%d",&n,&m,&a) == 3)
    {
        int d1 = (n+a-1)/a;
        int d2 = (m+a-1)/a;
        cout<<1LL*d1*d2<<endl;
    }
    return 0;
}

B

/*************************************************************************
 > File Name: B.cpp
 > Author: opas_chenxin
 > Mail: 1017370773@qq.com 
 > Created Time: 2016年05月06日 星期五 20时28分30秒    
*************************************************************************/
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<cmath>
using namespace std;
const int maxn = 5000000;
char A[maxn];
char B[maxn];
void solve1(int len)
{
    int a1 = 0;
    int loc = 0;
    while(loc<len)
    {
        if(A[loc] >= 'A' && A[loc] <= 'Z')
        {
            a1 = a1 * 26 + A[loc] - 'A' + 1; 
        }else
        {
            break;
        }
        loc++;
    }
    int b1 = 0;
    while(loc<len)
    {
        b1 = b1*10 + A[loc] -'0';
        loc++;
    }
   printf("R%dC%d
",b1,a1);
}
void solve2(int len)
{
  int b1 = 0;
  int loc=1;
  while(loc < len)
  {
    if(A[loc] == 'C') break;
    b1=b1*10+A[loc]-'0';
    loc++;
  }
  loc++;
  int a1 = 0;
  while(loc < len)
  {
      a1 = a1 * 10 + A[loc] - '0';
      loc++;
  }
  loc = 0;
  while(a1>0)
  {
    int v = a1%26;
    char c='Z';
    if(v != 0)
        c = 'A'+ v - 1;
    a1 -= c - 'A' + 1;
    a1 /= 26;
    B[loc ++] = c;
  }
  B[loc]='';
  for(int i = 0; i < loc/2; ++ i)
  {
      char tem = B[i];
      B[i] = B[loc-i-1];
      B[loc - i - 1] = tem;
  }
  printf("%s%d
",B,b1);
}
int main(int argc, char *argv[])
{
//    freopen("in","r",stdin);
    int cas;
    scanf("%d",&cas);
    for(int cc = 1; cc <= cas; ++ cc)
    {
        scanf("%s",A);
        int len = strlen(A);
        int num = 0, per = 0;
        for(int i = 0; i < len; ++ i)
        {
            if(A[i] >= 'A' && A[i] <= 'Z')
            {
                if(per == 0) 
                {
                    per = 1;
                    num++;
                }
            }else{
                per = 0;
            }
        }
        if(num == 1)
            solve1(len);
        else solve2(len);
    }
    return 0;
}

C

/*************************************************************************
 > File Name: C.cpp
 > Author: opas_chenxin
 > Mail: 1017370773@qq.com 
 > Created Time: 2016年06月15日 星期三 19时24分06秒    
*************************************************************************/
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<cmath>
using namespace std;
#define eps 1e-2
#define pi acos(-1.0)
int n,m;
double s,r,S,p;
double x[4],y[4],ang[4],L[4];
double dis(double x1,double y1,double x2,double y2)
{
    return sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
}
double gcd(double a,double b)
{
    if(a<eps) return b;
    if(b<eps) return a;
    return gcd(b,fmod(a,b));
}
int main(int argc, char *argv[])
{
    //freopen("in","r",stdin);
    for(int i=0; i<3; ++i)
    {
        scanf("%lf%lf",&x[i],&y[i]);
        
    }
    for(int i=0; i<3; ++i)
    {
        L[i]=dis(x[i],y[i],x[(i+1)%3],y[(i+1)%3]);
    }
    sort(L,L+3);
    p=(L[0]+L[1]+L[2])/2;
    s=sqrt(p*(p-L[0])*(p-L[1])*(p-L[2]));
    r=L[0]*L[1]*L[2]/(4*s);
    for(int i=0; i<2;++i)
        ang[i]=acos(1-L[i]*L[i]/(2*r*r));
    ang[2]=2*pi-ang[1]-ang[0];
    double unit=0;
    for(int i=0; i<3; ++i)
        unit=gcd(unit,ang[i]);
    printf("%.6f
",pi*r*r*sin(unit)/unit);
    return 0;
}