有点麻烦的一道模拟（官方题解好像有复杂度为$O(n)$DP的姿势?，感觉好烦，以后再细看~

在一些细节上调试了很久很久，囧RZ

/*ID: jusonal1PROG: beadsLANG: C++*/#include <iostream>#include <fstream>#include <string>#include <cstdio>#include <algorithm>#include <map>#include <cstring>using namespace std;char beads[1000];int n;int judge(int i) {    if(i < 1) return n;    else if(i > n) return 1;    else return i;}int find_(int i) {    int left = judge(i);    int right = judge(i+1);    int s_left = judge(i);    int s_right = judge(i+1);    int Left = judge(i);    int Right = judge(i+1);    int MAX = 0;    while(beads[left] == beads[s_left]||beads[left] == ‘w‘) {        ++MAX;        if(beads[s_left] == ‘w‘) s_left = judge(--s_left);        left = judge(--left);        if(left == Right) return MAX+1;    }    while(beads[right] == beads[s_right]||beads[right] == ‘w‘) {        ++MAX;        if(beads[s_right] == ‘w‘) s_right = judge(++s_right);        right = judge(++right);        if(left == right) return MAX+1;    }    return MAX;}int main () {    freopen("beads.in","r",stdin);    freopen("beads.out","w",stdout);    scanf("%d",&n);    for(int i = 1;i <= n;++i) scanf(" %c",&beads[i]);    int ans = 0;    for(int i = 1;i <= n;++i) {        ans = max(ans,find_(i));    }    printf("%d\n",ans);    return 0;}

USACO Section1.1PROB Broken Necklace