C. Magic Ship

 http://codeforces.com/contest/1117/problem/C

题意：给定起终点，n个风向（循环），顺风则移动2步，成角度则到角度的一步，逆风不动；问是否能到达终点；

思路：相当于先随风移动再自由移动，二分天数k，看到k天后在哪个位置，然后自由移动能不能到终点；

#include<algorithm>
#include<set>
#include<vector>
#include<queue>
#include<cmath>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<set>
#include<vector>
#include<queue>
#include<cmath>
#include<cstring>
#include<sstream>
#include<cstdio>
#include<ctime>
#include<map>
#include<stack>
#include<string>
using namespace std;

#define sfi(i) scanf("%d",&i)
#define pri(i) printf("%d\n",i)
#define sff(i) scanf("%lf",&i)
#define ll long long
#define mem(x,y) memset(x,y,sizeof(x))
#define INF 0x3f3f3f3f
#define eps 1e-6
#define PI acos(-1)
#define lowbit(x) ((x)&(-x))
#define zero(x) (((x)>0?(x):-(x))<eps)
#define fl() printf("flag\n")
ll gcd(ll a,ll b){while(b^=a^=b^=a%=b);return a;}
const int maxn=2e5+9;
const int mod=1e9+7;

template <class T>
inline void sc(T &ret)
{
    char c;
    ret = 0;
    while ((c = getchar()) < '0' || c > '9');
    while (c >= '0' && c <= '9')
    {
        ret = ret * 10 + (c - '0'), c = getchar();
    }
}

char s[maxn];
ll dx[maxn],dy[maxn];
ll n;
ll sx,sy,ex,ey;
bool ch(ll mid)
{
    ll nx=(mid/n)*dx[n]+dx[mid%n];
    ll ny=(mid/n)*dy[n]+dy[mid%n];
    if( abs(sx-ex+nx)+abs(sy-ey+ny) <=mid  ) return 1;
    return 0;
}
int main()
{

    cin>>sx>>sy>>ex>>ey;
    cin>>n;
    scanf("%s",s+1);
    for(int i=1;i<=n;i++)
    {
        dx[i]=dx[i-1];
        dy[i]=dy[i-1];
        if(s[i]=='U') dy[i]++;
        if(s[i]=='D') dy[i]--;
        if(s[i]=='L') dx[i]--;
        if(s[i]=='R') dx[i]++;
    }
    ll l=0;
    ll ans=-1;
    ll r=1e18;
    while(l<=r)
    {
        ll mid=(l+r)>>1;
        if(ch(mid))
        {
            ans=mid;
            r=mid-1;
        }
        else l=mid+1;
    }
    cout<<ans<<endl;
    return 0;
}