记录编号	459567	评测结果	AAAAAAAAAA
题目名称	爬山	最终得分	100
用户昵称	하루Kiev	是否通过	通过
代码语言	C++	运行时间	0.000 s
提交时间	2017-10-13 11:21:44	内存使用	0.00 MiB

# include "stdio.h"
# include "algorithm"
# define int long long
int step,dis,n,d,a,b,ans,top,las;
int cpp(){
    freopen("mountain.in","r",stdin);
	freopen("mountain.out","w",stdout);
    scanf("%lld%lld%lld%lld",&n,&d,&a,&b);
    n--;top=std::max(a,b);
    dis=std::abs(a-b);
    if(dis%d==0) step=dis/d;
    else step=dis/d+1;
    if(dis%d==0) las=0;
    else las=d-dis%d;
    ans+=(n-step)%2*las;
    ans+=(n-step)/2*d;
    ans+=top;
    printf("%lld",ans);
}int start=cpp();
signed main(){;}