/* ID: lxlenovos1 PROG: beads LANG: C++ */ #include <iostream> #include <fstream> #include <string> #include <vector> #include <string.h> #include <stdlib.h> #include <stdio.h> using namespace std; typedef struct ring { char a; struct ring *flink; struct ring *slink; } ring; ring* sring = NULL; ring* hring = NULL; /* the first node */ ring* ering = NULL; /* the end node */ int fcout = 0; int rcout = 0; ring* bring = NULL; void ring_pushback( ring* r, int n ) { static int i = 0; if ( i == 0 ) { sring = r; ++i; ++i; hring = r; } else { sring->slink = r; r->flink = sring; sring = r; /* the end node */ if ( i == n - 1 ) { sring->slink = hring; hring->flink = sring; ering = sring; } ++i; } } int get_maxresult( ring *gring ) { // cout the list ring* p = NULL; char tempvalue; fcout = 1; rcout = 1; p = gring; tempvalue = p->a; //cout << "temp1 is " << tempvalue << endl; do { //tempvalue = p->a; p = p->slink; //cout << p->a << endl; if ( p->a == tempvalue || p->a == 'w' || tempvalue == 'w' ) { if ( tempvalue == 'w' ) tempvalue = p->a; if ( 0 == fcout ) fcout = 1; ++fcout; //cout << "1" << endl; } else { //cout << "2" << endl; break; } }while( p != gring ); if ( p == gring ) goto __cout; p = gring->flink; tempvalue = p->a; //cout << "temp2 is " << tempvalue << endl; do { //tempvalue = p->a; p = p->flink; //cout << p->a << endl; if ( p->a == tempvalue || p->a == 'w' || tempvalue == 'w' ) { if ( tempvalue == 'w' ) tempvalue = p->a; if ( 0 == rcout ) rcout = 1; ++rcout; //cout << "1" << endl; } else { //cout << "2" << endl; break; } }while( p != gring ); return ( rcout + fcout ); __cout: rcout = 0; fcout--; return ( rcout + fcout ); } int main( void ) { ofstream fout( "beads.out" ); ifstream fin( "beads.in" ); int n, i, result; char temp; int max = 0; ring* g = NULL; //cin >> n; fin >> n; for ( i = 0; i < n; ++i ) { //cin >> temp; fin >> temp; ring* bread = new ring; bread->a = temp; bread->flink = NULL; bread->slink = NULL; ring_pushback( bread, n ); } //cout << "cin is end and the result is:" << endl; g = hring; for ( i = 0; i < n; ++i ) { result = get_maxresult( g ); //cout << "result is " << result << endl; if ( result > max ) max = result; if ( max >= n ) { max = n; break; } g = g->slink; //cout << g->a << endl; } //cout << max << endl; fout << max; fout << endl; exit( 0 ); }