记录编号	38128	评测结果	AAAAAAAAAA
题目名称	抗击SARS	最终得分	100
用户昵称	TBK	是否通过	通过
代码语言	C++	运行时间	0.003 s
提交时间	2012-04-13 14:54:47	内存使用	34.59 MiB

#include <cstdio> 
  
using namespace std; 
  
long double bac[3000000]; 
  
#define MAX(X,Y) ((X)>(Y)?(X):(Y)) 
#define MIN(X,Y) ((X)>(Y)?(Y):(X)) 
  
int main () 
{ 
    freopen("sars.in", "r", stdin); 
    freopen("sars.out", "w", stdout); 
  
    long double x, r, l, v; 
    scanf("%Lf%Lf%Lf%Lf", &x, &r, &l, &v); 
      
    long double ll = l*2, rr = r + 0.00001, xx = 0; 
    int head = 0, tail=1, ans=0; 
    bac[0] = x; 
  
    while (1) 
    { 
        for (int i=head; i<tail; i++) 
            if (MAX(bac[i] - rr, xx) <=  
                    MIN(bac[i] + rr, xx+v)) 
            { 
                ans++; 
                break; 
            } 
  
        xx += v; 
        if ((ll = ll/2) < 1) 
            break; 
        int ohead = head; 
        head = tail; 
        for (int i=ohead; i<head; i++) 
        { 
            bac[tail++] = bac[i] - ll; 
            bac[tail++] = bac[i] + ll; 
        } 
    } 
  
    printf("%d\n", ans); 
  
    return 0; 
}