https://www.luogu.org/problem/P1426
#include <iostream> using namespace std; int main(void) { double s,x; cin>>s>>x; char cRet = 'n'; double sBegin = s-x; double sEnd = s+x; int iBegin = 0; double now = 0; bool bDangerous = false; double speed = 7; if(sBegin < 0) { sBegin = 0; bDangerous = true; } while(now < sEnd) { if(bDangerous) { speed = speed*0.98; if(now+speed<=sEnd) { cRet = 'y'; break; } else { cRet = 'n'; break; } } now += speed; speed = speed*0.98; if(now >= sBegin && now <= sEnd) bDangerous = true; } cout << cRet << endl; return 0; }
