2014 Super Training #1 C Ice-sugar Gourd 模拟，扫描线

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
using namespace std;
#define N 100007

char ss[N];

int main()
{
    int len,ka,kb,i,j;
    int h,t,H,T;
    while(scanf("%d",&len)!=EOF && len)
    {
        scanf("%s",ss);
        H = T = 0;
        for(i=0;i<len;i++)
        {
            if(ss[i] == ‘H‘)
                H++;
            else
                T++;
        }
        if(H%2 || T%2)
        {
            puts("-1");
            continue;
        }
        int mid = len/2;
        h = t = 0;
        for(i=0;i<mid;i++)
        {
            if(ss[i] == ‘H‘)
                h++;
            else
                t++;
        }
        if(h == H/2 && t == T/2)
        {
            puts("1");
            printf("%d\n",mid);
            continue;
        }
        ka = 0;    //尾端
        kb = mid;  //前端
        int flag = 0;
        while(ka < mid-1)
        {
            if(ss[ka] == ‘H‘)  //尾端扫出去的字母
                h--;
            else
                t--;
            if(ss[kb] == ‘H‘)  //前端扫进来的字母
                h++;
            else
                t++;
            ka++,kb++;   //转
            if(h == H/2 && t == T/2)
            {
                flag = 1;
                break;
            }
        }
        if(flag)
        {
            puts("2");
            printf("%d %d\n",ka,kb);
        }
        else
            puts("-1");
    }
    return 0;
}