Codeforces Round 55 (Rated for Div. 2) B - Vova and Trophies

题目：

http://codeforces.com/contest/1082/problem/B

题解：

代码：
 

//2
#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
#define MAXN 100010

char str[MAXN];
int l[MAXN],r[MAXN];

int main()
{
    int i;
    int allnum;
    int n;
    int ans;

    scanf("%d",&n);
    scanf("%s",str+1);
    allnum=0;
    for(i=1;i<=n;i++)
    {
        if(str[i]=='G')
        {
            allnum++;
            l[i]=l[i-1]+1;
        }
    }
    for(i=n;i>=1;i--)
    {
        if(str[i]=='G')
            r[i]=r[i+1]+1;
    }
    ans=0;
    if(allnum==n)
    {
        printf("%d\n",n);
        return 0;
    }
    for(i=1;i<=n;i++)
    {
        if(str[i]=='S')
        {
            if(l[i-1]+r[i+1]==allnum)
                ans=allnum;
            else
                ans=max(ans,l[i-1]+r[i+1]+1);
        }
    }
    printf("%d\n",ans);
    return 0;
}