花大力气写的模拟。。。等搜索练好了再回来做，另外把测试数据发一下。。
/*
ID:linyvxi1
PROG:beads
LANG:C++
*/
#include <stdio.h>
#include <string.h>
int main()
{
FILE* fin=fopen("beads.in","r");
FILE* fout=fopen("beads.out","w");
int n;
char str[400];
fscanf(fin,"%d",&n);
fscanf(fin,"%s",str);
bool flag1=false,flag2=false;
int i=0,j=strlen(str)-1;
char stat=str[0];
//while(i<=j&&(str[i]==str[i+1]||str[i+1]=='w'||str[i]=='w'))
while(i<=j&&(str[i]==stat||str[i]=='w'))
i++;
stat=str[strlen(str)-1];
// while(j>=0&&(str[j]==str[j+1]||str[j]=='w'||str[j+1]=='w'))
while(j>=0&&(str[j]==stat||str[j]=='w'))
j--;
int max,temp=0;
if(i>=j){
fprintf(fout,"%d\n",strlen(str));
return 0;
}//如果全相同。。。
else max=i+strlen(str)-1-j;
for(i=1;i<=strlen(str)-1;i++){
int n=i,m=i-1,k;
k=i-1;
while(str[k]=='w')
k++;
stat=str[k];
// stat=str[i-1];
while(m>=0&&(str[m]==stat||str[m]=='w'))//标志位
m--;//左边是i-1-m个
k=n;
while(str[k]=='w')
k++;
stat=str[k];
while(n<=strlen(str)-1&&(str[n]==stat||str[n]=='w'))
n++;//右边是n-i个
if(m!=-1&&n!=strlen(str)){//如果都没数到头
int num=i-1-m+n-i;
if(num>max)
max=num;
}
// stat=str[i-1];
else if(m==-1&&n!=strlen(str)){//如果左边到头了右边没到头
k=i-1;
while(str[k]=='w')
k++;
stat=str[k];
if(str[strlen(str)-1]==stat||str[strlen(str)-1]=='w'){//如果左边还能继续往下走
m=strlen(str)-1;
while(str[m]==stat||str[m]=='w')
m--;//右边是n-i个
//int sum=n-i+1+i-0+1+strlen(str)-1-m+1;
int sum=n-i+strlen(str)-1-m+i;
if(sum>max)
max=sum;
}
else {
int sum=i+n-i;
if(sum>max)
max=sum;
}
}
// stat=str[i];
else if(m!=-1&&strlen(str)==n){//如果左边没到头右边到头了
k=i;
while(str[k]=='w')
k++;
stat=str[k];
if(str[0]=='w'||str[0]==stat){//如果右边还能继续走下去
n=0;
while(str[n]==stat||str[n]=='w')
n++;//又走了n个
// int sum=n-0+1+i-1-m+1+strlen(str)-1-i+1;
int sum=n+i-1-m+strlen(str)-1-i+1;
if(sum>max)
max=sum;
}
else{
// int sum=i-1-m+1+strlen(str)-1-i+1;
int sum=i-1-m+strlen(str)-i;
if(sum>max)
max=sum;
}
}
else{//两边都到头了
max=strlen(str);
break;
}
}
fprintf(fout,"%d\n",max);
}
Here are the test data inputs:
------- test 1 ---- 29 wwwbbrwrbrbrrbrbrwrwwrbwrwrrb ------- test 2 ---- 3 rrr ------- test 3 ---- 77 rwrwrwrwrwrwrwrwrwrwrwrwbwrwbwrwrwrwrwrwrwrwrwrwrwrwrwrwrwrwrwrwrwrwrwrwrwrwr ------- test 4 ---- 17 wwwwwwwwwwwwwwwww ------- test 5 ---- 50 bbrrrbrrrrrrrrbrbbbrbrrbrrrrbbbrbrbbbbbrbrrrbbrbbb ------- test 6 ---- 8 rrwwwwbb ------- test 7 ---- 200 rrrrrrrrrrrrrrrrrrrrbbbbbbbbbbbbbbbbbbbbrrrrrrrrrrrrrrrrrrrrbbbbbbbbbbbbbbbbbbbbrrrrrrrrrrrrrrrrrrrrbbbbbbbbbbbbbbbbbbbbrrrrrrrrrrrrrrrrrrrrbbbbbbbbbbbbbbbbbbbbrrrrrrrrrrrrrrrrrrrrbbbbbbbbbbbbbbbbbbbb ------- test 8 ---- 350 rrbbrbbbwbwwbwbbbbwwrrbbwbrwbrwbbbrbrwrwbrwwwrrbbrrwrbbrwbwrwwwrbrwwwwwrwbwwwrrbrrbbbrbrbbbrbbbrbbwbbbbbrbrrbrwwbrrrrwbwrwrbbwbwrbrbrwwbrrbwbrwwbwwwbrbwrwbwbrbbbwrbwwrrrbwbwbbbbbrrwwwrbrwwrbbwrbbrbbrbwrrwwbrrrbrwbrwwrbwbwrrrbwrwrrbrbbwrwrbrwwwrwbwrrwwwwrrrwrrwbbwrwwrwrbwwbwrrrrbbwrbbrbwwwwwbrbbrbbrbrwbbwbwwbbbbbwwwrbwwbbbwrwwbbrrwrwbwrrwwwrrrwrrwww ------- test 9 ---- 333 rwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwbrwb