C++_USACO_Broken Necklace

/*
PROB:beads
LANG:C++
*/
#include<iostream>
#include<string>
#include <cstdlib>
#include <cstring>
#include<fstream>
using namespace std;
string strReverse(string str1){
int len=str1.size();
string str2=str1;
char *end=&str1[0]+len-1;
for(int i=0;i<len;i++)
if(end>&str1[0]){
str2[i]=end[0];
end--;
}
else if(end==&str1[0]){
str2[i]=end[0];
break;
}
return str2;
}
int first_maxLen(string newstr){
int i=0;
int n=newstr.size();
int temp_len=0;
char br=' ';
if(newstr[0]=='w'){
while(i<n){
if(newstr[i]=='w' || newstr[i]==br){
temp_len++;
i++;
continue;
}
if(br==' '){
br=newstr[i];
temp_len++;
i++;
continue;
}
if(br!=newstr[i])
break;
}
}
else{
br=newstr[0];
while(i<n){
if(newstr[i]==br||newstr[i]=='w'){
temp_len++;
i++;
continue;
}
else
break;
}
}
return temp_len;
}
int main(){
ifstream ifs("beads.in");
ofstream ofs("beads.out");
int n;
int back_len;
int forward_len;
int new1_firstmax;
int new2_firstmax;
int new1_finalmax=0;
int new2_finalmax=0;
int max=0;
int tempmax=0;
string necklace="";
ifs>>n;
if(n>350||n<3)
return 0;
ifs>>necklace;
string reverse_lace=strReverse(necklace);
new1_finalmax=first_maxLen(necklace);
new2_finalmax=first_maxLen(reverse_lace);
if(reverse_lace.compare(necklace)==0){
max=new1_finalmax;
}
else{
max=new1_finalmax+new2_finalmax;
}
string back_str="";
string forward_str="";
string newstr1="";
string newstr2="";
for(int i=0;i<n-1;i++){
back_str=&necklace[i+1];
back_len=back_str.size();
forward_len=n-back_len;
forward_str=necklace.substr(0,forward_len);
newstr1=strcat(&back_str[0],&forward_str[0]);
newstr2=strReverse(newstr1);
new1_firstmax=first_maxLen(newstr1);
new2_firstmax=first_maxLen(newstr2);
if(newstr1.compare(newstr2)==0)
tempmax=new1_firstmax;
else{
tempmax=new1_firstmax+new2_firstmax;
}
if(tempmax>max)
max=tempmax;
}
ofs<<max<<endl;
return 0;
}

> Run 6: Execution error: Your program had this runtime error:
Illegal file open (/dev/tty). The program ran for 0.000 CPU
seconds before the error. It used 3500 KB of memory.

------ Data for Run 6 [length=11 bytes] ------
8
rrwwwwbb
----------------------------

Test 6: SIGNAL 50 (0.000 secs, 3500 KB)

#include<fstream>
using namespace std;

int main()
{
int num,max=0,n,i,j,k;
char *p,symbol1,symbol2;
ifstream fin("beads.in");
ofstream fout("beads.out");

fin>>n;
p=new char[n+1];
fin>>p;

for(i=n;i<2*n;++i){
if(p[i%n]!=p[(i+1)%n]){
symbol1=p[i%n]!='w'?p[i%n]:(p[(i+1)%n]=='r'?'b':'r');
symbol2=symbol1=='r'?'b':'r';
num=0;

for(j=i;j>i-n;--j){
if(p[j%n]==symbol1||p[j%n]=='w') ++num;
else break;
}
for(k=i+1;k<j+n+1;++k){
if(p[k%n]==symbol2||p[k%n]=='w') ++num;
else break;
}

max=max>num?max:num;
}
}

if(max==0) max=n;
fout<<max<<endl;
fin.close();
fout.close();
delete [] p;

return 0;
}