usaco_beads.cpp

usaco自己做的1到5章的代码

/*
ID: wangyuc2
PROG: beads
LANG: C++
*/

#include<iostream>
#include<cstring>
#include<fstream>

using namespace std;
int main()
{
 ifstream fin("beads.in");
 ofstream fout("beads.out");
 int i,j,k,n,maxl,maxr,max=0;
 char str[701];
 char ch;
 fin>>n;
 fin>>str;
 for(i=0;i<n;i++)
 {
     if(str[i]== 'w') continue;
     maxl=0;maxr=0;
     j=0;
     ch=str[i];
     while(1)
     { 
         if(j==n) break;
         if(str[(i+j)%n] == ch) {maxl++;j++;continue;}
         else if(str[(i+j)%n] == 'w') {maxl++;j++;continue;}
         else break;
        
     }
     j=0;
     while(str[(i+n-j-1)%n]=='w' && j<n)
     {
          j++;
     }
     ch=str[(i+n-j-1)%n];
     j=0;
     while(1)
     {
         if(j==n-maxl) break;
         if(str[(i-j+n-1)%n] == ch ||str[(i+n-j-1)%n] == 'w') {maxr++;j++;continue;}
         //else if() {maxl++;j++;continue;}
         else break;
           
     }
     if(maxl+maxr>max) max=maxl+maxr;
 } 
 if(max==0) max=n;
 if(max>n) max/=2;
 fout<<max<<endl;
 //system("PAUSE");
 return 0;
}