不含重复字符的最长子串--O(n)

#include <iostream>
#include <cstdlib>
#include <string>
using namespace std;
int main()
{
char * s = "abbc";

int  hash[256];
for (int i = 0; i < 256; i++)
hash[i] = -1;

int cur_start = 0;
int max_start = 0;

int cur_size = 1;
int max_size = 1;
hash[s[0]] = 0;
for (int i = 1; i < strlen(s); i++)
{

if (hash[s[i]] == -1)
{
cur_size++;
hash[s[i]] = i;
if (cur_size > max_size)
{
max_size = cur_size;
max_start = cur_start;
}
}
else
{
cur_start = hash[s[i]] + 1;
cur_size = i - hash[s[i]];
hash[s[i]] = i;
}
}
cout << "max_start: " << max_start << endl;
cout << "max_size: " << max_size << endl;
printf("%.*s/n", max_size, s + max_start);
system("pause");
return 0;
}