Codeforces Round #363 (Div. 2)

 A. Launch of Collider

根据字符左移或右移，输出第一次碰撞的位置，不然输出-1

#include <cstdio>
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
#define LL long long
char ch[200005];
LL a[200005],ans;
int n;
bool f=0;
int main()
{
    cin>>n;
    cin>>ch;
    for(int i=0;i<n;i++)
    {
        cin>>a[i];
    }
    ans=1e9;
    for(int i=1;i<n;i++)
    {
        if(ch[i]=='L'&&ch[i-1]=='R')
        {
            ans=min(ans,(a[i]-a[i-1])/2 );
            f=1;
        }
    }
    if(f)
    cout<<ans<<endl;
    else puts("-1");
}